Lucia finds that (3x²+3x+5)+(7x²-9x+8)=10x²-12x+13. what error did lucia make?

a)she found the difference instead of the sum.
b)she combined the terms 3x² and 7x² incorrectly.
c)she combined the terms 3x and –9x incorrectly.
d)she did not combine all like terms.

A)a square brown tarp has a square green patch green in the corner the side length of the tarp is (x + 8) and the side length of the patch is x what is the area of the brown part of the tarpb)a square red placemat has a gold square in the corner the side length of the gold square is (x - 2) inches with the width of the red region is 4 in what is the area of the red part of the placemat