Answer:
i think 80/3
Step-by-step explanation:
Answer:
No mistake
Step-by-step explanation:
2x + y = 5
x - 2y = 10
y = 5 - 2x
x - 2(5 - 2x) = 10
x - 10 + 4x = 10
5x - 10 = 10
5x = 20
x = 4
2(4) + y = 5
y = -3
She made no mistake
You can check by plugging in x = 4 and y = -3 into the original equations . They fit exactly.
Answer:
x = -7 ±3i
Step-by-step explanation:
(x+7)^2+9=0
Subtract 9 from each side
(x+7)^2+9-9=0-9
(x+7)^2=-9
Take the square root of each side
sqrt((x+7)^2) = ±sqrt(-9)
We know sqrt(ab) = sqrt(a) sqrt(b)
x+7 = ±sqrt(-1) sqrt(9)
We know that sqrt(-1) is the imaginary number i
x+7 = ±i *3
x+7 =±3i
Subtract 7 from each side
x+7-7 = -7 ±3i
x = -7 ±3i
first is false and second is also false all ate false