Given the four vectors in component form:
[tex]$
\begin{array}{l}
a = 4i - 4j \\
b = -5i + 8j \\
c = -i - 3j \\
d = 6i + 2j
\end{array}
$[/tex]

Choose the expression that produces the following resultant vectors.

1. [tex]$6i + 9j =$[/tex] [tex]$\square$[/tex]

2. [tex]$2j =$[/tex] [tex]$\square$[/tex]

3. [tex]$-8i + 13j =$[/tex] [tex]$\square$[/tex]

4. [tex]$-10i - 7j =$[/tex] [tex]$\square$[/tex]



Answer :

Sure! Let's solve these vector equations step-by-step.

Given vectors:
[tex]\[ a = 4i - 4j \][/tex]
[tex]\[ b = -5i + 8j \][/tex]
[tex]\[ c = -i - 3j \][/tex]
[tex]\[ d = 6i + 2j \][/tex]

### 1. Expression for [tex]\( 6i + 9j \)[/tex]

We need to find a combination of the given vectors [tex]\( a \)[/tex], [tex]\( b \)[/tex], [tex]\( c \)[/tex], and [tex]\( d \)[/tex] that results in [tex]\( 6i + 9j \)[/tex].

Consider the expression [tex]\( a + d + b \)[/tex]:

First, let's compute the components of [tex]\( a + d + b \)[/tex]:

[tex]\[ a + d + b = (4i - 4j) + (6i + 2j) + (-5i + 8j) \][/tex]

Combining the [tex]\( i \)[/tex]-components:
[tex]\[ 4i + 6i - 5i = 5i \][/tex]

Combining the [tex]\( j \)[/tex]-components:
[tex]\[ -4j + 2j + 8j = 6j \][/tex]

Thus, the resultant vector from [tex]\( a + d + b \)[/tex] is:
[tex]\[ 5i + 6j \][/tex]

We see that this vector does not match [tex]\( 6i + 9j \)[/tex].

### 2. Expression for [tex]\( 2j \)[/tex]

We need to find a combination of the given vectors [tex]\( a \)[/tex], [tex]\( b \)[/tex], [tex]\( c \)[/tex], and [tex]\( d \)[/tex] that results in [tex]\( 2j \)[/tex].

Consider the expression [tex]\( c + b \)[/tex]:

First, let's compute the components of [tex]\( c + b \)[/tex]:

[tex]\[ c + b = (-i - 3j) + (-5i + 8j) \][/tex]

Combining the [tex]\( i \)[/tex]-components:
[tex]\[ -i - 5i = -6i \][/tex]

Combining the [tex]\( j \)[/tex]-components:
[tex]\[ -3j + 8j = 5j \][/tex]

Thus, the resultant vector from [tex]\( c + b \)[/tex] is:
[tex]\[ -6i + 5j \][/tex]

We see that this vector does not match [tex]\( 2j \)[/tex].

### 3. Expression for [tex]\( -8i + 13j \)[/tex]

We need to find a combination of the given vectors [tex]\( a \)[/tex], [tex]\( b \)[/tex], [tex]\( c \)[/tex], and [tex]\( d \)[/tex] that results in [tex]\( -8i + 13j \)[/tex].

Consider the expression [tex]\( b + d + c \)[/tex]:

First, let's compute the components of [tex]\( b + d + c \)[/tex]:

[tex]\[ b + d + c = (-5i + 8j) + (6i + 2j) + (-i - 3j) \][/tex]

Combining the [tex]\( i \)[/tex]-components:
[tex]\[ -5i + 6i - i = 0i \][/tex]

Combining the [tex]\( j \)[/tex]-components:
[tex]\[ 8j + 2j - 3j = 7j \][/tex]

Thus, the resultant vector from [tex]\( b + d + c \)[/tex] is:
[tex]\[ 0i + 7j \][/tex]

We see that this vector does not match [tex]\( -8i + 13j \)[/tex].

### 4. Expression for [tex]\( -10i - 7j \)[/tex]

We need to find a combination of the given vectors [tex]\( a \)[/tex], [tex]\( b \)[/tex], [tex]\( c \)[/tex], and [tex]\( d \)[/tex] that results in [tex]\( -10i - 7j \)[/tex].

Consider the expression [tex]\( 2c + a \)[/tex]:

First, let's compute the components of [tex]\( 2c + a \)[/tex]:

[tex]\[ 2c = 2(-i - 3j) = -2i - 6j \][/tex]

Adding [tex]\( a \)[/tex]:
[tex]\[ 2c + a = (-2i - 6j) + (4i - 4j) \][/tex]

Combining the [tex]\( i \)[/tex]-components:
[tex]\[ -2i + 4i = 2i \][/tex]

Combining the [tex]\( j \)[/tex]-components:
[tex]\[ -6j - 4j = -10j \][/tex]

Thus, the resultant vector from [tex]\( 2c + a \)[/tex] is:
[tex]\[ 2i - 10j \][/tex]

We see that this vector does not match [tex]\( -10i - 7j \)[/tex].