Answer:
- 18y = 1
Step-by-step explanation:
Adding the 2 equations term by term on both sides gives
(- 5x + 5x) + (- 9y - 9y) = (3 - 2), that is
0 + (- 18y) = 1
- 18y = 1
 
        
             
        
        
        
Answer:
8
Step-by-step explanation:
plug in the number 4, it would be 5•4-12
Do 5•4=20
20-12=8
 
        
             
        
        
        
Answer:
1.a=2
2.  C  x=2  and x=-3
Step-by-step explanation:
The standard form for the quadratic function is  
ax^2 +bx+c
so  we need to rewrite the function to be in this form
2x^2 -10 = 7x
Subtract 7x from each side
2x^2 -7x-10 = 7x-7x
2x^2 -7x-10 = 0
a =2, b= -7  c=-10
2.  The quadratic formula is
-b ± sqrt(b^2 -4ac)
----------------------------
2a
2x^2 + 2x=12
Lest get the equation in proper form
2x^2 + 2x-12 = 12-12
2x^2 +2x-12 =0
a=2  b=2 c=-12
Lets substitute what we know
-2 ± sqrt(2^2 -4(2)(-12))
----------------------------
2(2)
-2 ± sqrt(4+96)
----------------------------
2(2)
-2 ± sqrt(100)
----------------------------
4
-2 ± 10
----------------------------
4
-2 + 10               -2-10
-----------   and  --------------
4                             4
8/4   and -12/4
2  and -3