Answer:
C. 3, -7
Step-by-step explanation:
x^2 +4x-21 =0
Factor
What 2 numbers multiply to -21 and add to 4
7*-3 = -21
7-3 = 4
(x+7) (x-3) =0
Using the zero product property
x+7 =0 x-3=0
x+7-7=0-7 x-3+3=0+3
x = -7 x=3
Answer:
4 large , 14 small
Step-by-step explanation:
35*x +20*(18-x)=420
35x +360-20x=420
35x-20x=420-360=60
15x= 60
x =4
4 large 14 small
Answer:
4+11=15
Step-by-step explanation:
c=4 11=b
4(c) + 11(d) = 15