Answer:
add 21 to both sides to get everything on one side
x^2 - 10x + 21 = 0
do factorization, guess and check
(x - 7) (x -3) = 0
x =7, and x =3
Answer:
Step-by-step explanation:
x²+10x+21=0
x²+10x+(10/2)²-(10/2)²+21=0
x²+10x+25-25+21=0
(x+5)²-4=0
(x+5)²=4
(x+y)²=(x+y)(x+y)=x(x+y)+y(x+y)=x²+xy+xy+y²=x²+2xy+y²
(x+y)²=x²+2xy+y²
coefficient of x=2y
y²=[(coefficient of x)/2]²=(2y/2)²=y²
Is this simultaneous equations?
if yes then the first step is
make one of the unknown as the subject
The vertex-form equation is
y = a(x+1)² -16
Putting in the y-intercept values, we have
-15 = a(0+1)² -16
1 = a . . . . . . . . . . . add 16
Then the x-intercepts can be found where y=0.
0 = (x+1)² -16
16 = (x+1)²
±4 = x+1
x = -1 ± 4 =
{-5, 3}
Yes. The umbrella is smaller than the suitcase. The suitcase is 81'^2, but the umbrella is 14