Answer:
1) 2x^2 -8x
2) 18x^2 -45x
Step-by-step explanation:
These problems make use of the distributive property. It tells you how you can use or eliminate parentheses as you may need.
a(b + c) = ab + ac . . . . . . . the outside factor multiplies each inside term
Of course, the usual rules of multiplication of positive and negative numbers apply. If the number of minus signs in a product is odd, the result is negative; otherwise the result is positive.
1. 2x(x -4) = (2x)(x) + (2x)(-4) = 2x^2 -8x
2. -9x(5 -2x) = (-9x)(5) + (-9x)(-2x) = -45x +18x^2 = 18x^2 -45x
3. She used the algebra tiles correctly.
- The headers correctly represent -2x-2 and 2x-1
- Each product has the correct sign (-- = +, -+ or +- = -)
- Each product has the correct power of x
