Answer:
(- 2, 4 )
Step-by-step explanation:
y = 2x + 8 → (1)
y = - 2x → (2)
substitute y = 2x + 8 into (2)
2x + 8 = - 2x ( add 2x to both sides )
4x + 8 = 0 ( subtract 8 from both sides )
4x = - 8 ( divide both sides by 4 )
x = - 2
substitute x = - 2 into (2)
y = - 2(- 2) = 4
solution is (- 2, 4 )
Answer:
c This is the direct variation
Step-by-step explanation:
The equation for direct variation is y= kx
Solving this for k
y/x =k
So y/x must be a constant
a. 9/3 =3
2/7 does not =3 so this is not a direct variation
b 1/2 = .5
-3/6 = -.5
This is not the same so this is not a direct variation
c. 27/9 =3
18/6 =3
9/3 =3
This is a direct variation with a constant of 3
d 5/-7 = -5/7
1/-3 = -1/3
This is not the same so this is not a direct variation
"of" means multiply and "is" means equal
1.
x = 14
x = 14(3) <em>multiply both sides by 3 to isolate "x"</em>
x = 42
2.
x = 14
x = 14(5) <em>multiply both sides by 5 to isolate "x"</em>
x = 70
3.
x = 14
2x = 14(5) <em>multiply both sides by 5 </em>
2x = 70
x = 35 <em>divide both sides by 2 to isolate "x"</em>
4.
x = 14
7x = 14(8) <em>multiply both sides by 8 </em>
7x = 112
x = 16 <em>divide both sides by 7 to isolate "x"</em>
Answers: 42, 70, 35, 16
0.001 x 425 = .425
answer C. $0.425