Answer :

FIrst we have to transform our equation into slope y-intercept form y=ab+x
7x+2y=-10   /-7x  subtract 7x both sides
2y=-7x-10    /:2    divide by 2 both sides
y=-7/2-5
Now we can read value of parameter b, which is b=-5. Its the our result, so -5.
subtract 7x from both sides
2y= -10-7x
sub 0 in for x
2y= -10-7(0)
divide both sides by 2
y= -5