Which arrangement of blocks has the least surface area?

Which formula gives the area of a triangle? a=1/2(b+h)

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.

1. find the area of the unshaded square 2. find the area of the large square 3. what is the area of the frame represented by the shaded region show