Answer:
x=3
x=−3
Step-by-step explanation:
2x^2 - 5 = 13
Subtract 13 from both sides.
2x^2 - 5 - 13 = 0
Subtract 13 from −5 to get −18.
2x^2 - 18 = 0
Divide both sides by 2.
x^2 - 9 = 0
Consider x^2−9. Rewrite x^2−9 as x^2−3^2. The difference of squares can be factored using the rule: a^2−b^2=(a−b)(a+b).
(x−3)(x+3)=0
To find equation solutions, solve x−3=0 and x+3=0.
x=3
x=−3
Answer:
33.33 mL of 50%
66.67 of 80%
Step-by-step explanation:
Let x = quantity of 50% methane.
Then,
0.50x + 0.80(100 - x) = 100 × 0.70
⇒ 0.50 x + 80 - 0.80 x = 70
⇒ -0.30 x = 70 - 80
⇒ -0.30 x = -10
⇒ 
⇒ x = 33.33 mL of 50%
and, 100 - 33.33 = 66.67 of 80%
15 I think i'm sorry if i'm wrong
The side of the congruent side of the triangle should be greater than 7 feet.
5x=-10-5y
Add 5y for both side
5x+5y=-10
-
5x+10y=-25
=
-5y=15
Divided -5 for both side
y=-3
5x+10y=-25
5x+10(-3)=-25
5x-30=-25
Add 30 for both side
5x=5
Divided 5 for both side
x=1. Hope it help!
