Full question:
For each multiplication expression, sketch an area model. Label the dimensions and the area of each part. Then write an equation showing that the area as a product equals the area as a sum. a. (x+1)(x+2), b. 3(2x+5), c. (2x-3)(x+2), d. (x-1)(y-1), e. -2y(y+3), f. (-x+1)(3x+y-4)
Answer and explanation:
a. (x+1)(x+2)= x×x+x×2+1×x+1×2
The dimensions (length and width) is x+1 and x+2
b. 3(2x+5) = 3×2x+3×5
The dimensions is 3 and 2x+5
c. (2x-3)(x+2)= 2x×x+2x×2-3×x-3×+2
The dimensions are 2x-3 and x+2
d. (x-1)(y-1)= x×y+x×-1-1×y-1×-1
Dimensions are x-1 and y-1
e. -2y(y+3)= -2y×y-2y×3
Dimensions are -2y and y+3
f. (-x+1)(3x+y-4)= -x×3x-x×y-x×-4+1×3x+1×y+1×-4
Dimensions are -x+1 and 3x+y-4
