You first must distribute the negative sign to 3x+7, giving you -3x+7. Then you combine like terms (the 9x+(-3x) and 10+(-7)). This would give you 6x+3
To find perimeter, you use this equation for a parallelogram: 2l+2w=p Let’s not put the numbers in, 2(12)+2(8) 24+16 40 So b, 40 yards is how much he walked.