Answer:
C
Step-by-step explanation:
x²+2x-15 = x²-3x+5x-15 = x(x-3)+5(x-3)=(x+5)(x-3)
or delta:
∆=2²-4*1*(-15)=4+60=64
√∆=8
x1 = (-2+8)/2 = 3
x2=(-2-8)/2=-5
and 4x+20 = 4(x+5)
The same is (x+5), so it is GCF. answer C
Answer:
82/13
Step-by-step explanation:
Answer:
80/140 = (80:20)/(140:20) = 4/7
4/7 = (4*4)/(7*4) = 16/28
4/7 = (4*5)/(7*5) = 20/35 not 20/28 not 20/32
4/7 = (4*5.5)/(7*5.5) = 22/38.5 not 22/37
