Answer: 9.9 Original answer is 10.5
Step-by-step explanation:
I think it B or D I hope i don’t get it wrong
Answer:
x = (1/2) (-9 ± √73)
Step-by-step explanation:
Using completing the square method
x²+9x+2=0
x²+9x = -2 (complete the square by adding (9/2)² to both sides)
x²+9x + (9/2)² = -2 + (9/2)²
( x + (9/2) )² = -2+ (9/2)²
( x + (9/2) )² = -2+ (81/4)
( x + (9/2) )² = 73/4
x + (9/2) = ± √(73/4)
x + (9/2) = ± √(73) / 2
x = -(9/2) ± √(73) / 2 (factorize out (1/2) )
x = (1/2) (-9 ± √73)
Answer:
x = - 7, y = 6
Step-by-step explanation:
7x + 7y = - 7 -----> equation 1
- 10x - 7y = 28 -----> equation 2
Add equations 1 & 2,
7x + 7y = - 7
- 10x - 7y = 28
___________
- 3x + 0 = 21
- 3x = 21
x = 21 / - 3
x = - 7
Substitute x = - 7 in equation 1,
7x + 7y = - 7
7y + 7x = - 7
7y + 7 ( - 7 ) = - 7
7y - 49 = - 7
7y = - 7 + 49
7y = 42
y = 42 / 7
y = 6
