Xy is the number
A) x + y = 7
B) 10y + x = 10x + y + 9
collecting terms of equation B
B) -9x + 9y = 9
multiplying A) by 9
A) 9x + 9y = 63 then adding it to equation B)
B) -9x + 9y = 9
18y = 72
y = 4
x = 3
The number is 34
1, B
2, C
3, C
4, C
5, a
6, b
7, b
8, C
9, a I think.
Hoped this helps.
Answer:
-7/2 = -2(x-1/2)^2
Step-by-step explanation:
0 = –2x^2 + 2x + 3
Subtract 3 from each side
-3 = –2x^2 + 2x
Factor out the -2
-3 =- 2(x^2 -x)
Take the coefficient of x and divide by 2 and square it
-1 /2 = -1/2 ^2 = 1/4
Add it to each side Remember the -2 on the outside so we need to multiply it by -2
-2 *1/4 = -1/2
-3 -1/2= -2(x^2 -x +1/4)
-7/2 = -2(x^2 -x +1/4)
-7/2 = -2(x-1/2)^2
X>_ 0
If you don’t understand that then x is greater than or equal to 0