5.3. Add (3x-7x² + 4) and (3 + 2x - x²)
5.4.
James and Mpho together have 127 stamps. James has 4 more than
twice as many as Mpho. How many stamps do each of them have?
1241
(3)
(5)



Answer :

Certainly! Let's solve each problem step-by-step.

### Question 5.3: Add the polynomials [tex]\( (3x - 7x^2 + 4) \)[/tex] and [tex]\( (3 + 2x - x^2) \)[/tex]

Step-by-Step Solution:

1. Write down the given polynomials:

[tex]\[ P1 = 3x - 7x^2 + 4 \][/tex]
[tex]\[ P2 = 3 + 2x - x^2 \][/tex]

2. Combine like terms:

- Combine the [tex]\( x^2 \)[/tex] terms:
[tex]\[ -7x^2 - x^2 = -8x^2 \][/tex]
- Combine the [tex]\( x \)[/tex] terms:
[tex]\[ 3x + 2x = 5x \][/tex]
- Combine the constant terms:
[tex]\[ 4 + 3 = 7 \][/tex]

3. Write the resulting polynomial:

[tex]\[ P1 + P2 = -8x^2 + 5x + 7 \][/tex]

Final Answer:
[tex]\[ -8x^2 + 5x + 7 \][/tex]

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### Question 5.4: James and Mpho together have 127 stamps. James has 4 more than twice as many as Mpho. How many stamps do each of them have?

Step-by-Step Solution:

1. Define the variables:

Let [tex]\( m \)[/tex] be the number of stamps Mpho has.

2. Express James' number of stamps in terms of [tex]\( m \)[/tex]:

James' stamps = [tex]\( 2m + 4 \)[/tex]

3. Set up the equation based on the total number of stamps:

[tex]\[ m + (2m + 4) = 127 \][/tex]

4. Simplify the equation:

[tex]\[ 3m + 4 = 127 \][/tex]

5. Solve for [tex]\( m \)[/tex]:

Subtract 4 from both sides:
[tex]\[ 3m = 123 \][/tex]
Divide both sides by 3:
[tex]\[ m = 41 \][/tex]

So, Mpho has [tex]\( 41 \)[/tex] stamps.

6. Calculate the number of stamps James has:

[tex]\[ 2m + 4 = 2(41) + 4 = 82 + 4 = 86 \][/tex]

Final Answer:
- Mpho has [tex]\( 41 \)[/tex] stamps.
- James has [tex]\( 86 \)[/tex] stamps.