Answer:
x = ±6
Step-by-step explanation:
x^2/4=9
Multiply by 4 on each side
x^2/4 *4=9*4
x^2 = 36
Take the square root of each side
sqrt(x^2) = ±sqrt(36)
x = ±6
Answer:
Step-by-step explanation:
Answer:
- Walnuts cost $1.75, chocolate chips cost $2.75
Step-by-step explanation:
<h3>Let the costs be:</h3>
- Walnuts - x
- Chocolate chips - y
<h3>Set equations as per question</h3>
For 7 pounds of walnuts and 9 pounds of chocolate chips, the total cost is $37:
For 5 pounds of walnuts and 3 pounds of chocolate chips, the total cost is $17:
<h3>Solve the system by elimination</h3>
Multiply the second equation by 3 and subtract the first equation, solve for x:
- 3(5x + 3y) - (7x + 9y) = 3(17) - 37
- 15x + 9y - 7x - 9y = 51 - 37
- 8x = 14
- x = 14/8
- x = 1.75
Find the value of y:
- 7*1.75 + 9y = 37
- 12.25 + 9y = 37
- 9y = 37 - 12.25
- 9y = 24.75
- y = 24.75/9
- y = 2.75
<span>Simplifying
4x + 20 = 6x + -10
Reorder the terms:
20 + 4x = 6x + -10
Reorder the terms:
20 + 4x = -10 + 6x
Solving
20 + 4x = -10 + 6x
Move all terms containing x to the left, all other terms to the right.
Add '-6x' to each side of the equation.
20 + 4x + -6x = -10 + 6x + -6x
Combine like terms: 4x + -6x = -2x
20 + -2x = -10 + 6x + -6x
Combine like terms: 6x + -6x = 0
20 + -2x = -10 + 0
20 + -2x = -10
Add '-20' to each side of the equation.
20 + -20 + -2x = -10 + -20
Combine like terms: 20 + -20 = 0
0 + -2x = -10 + -20
-2x = -10 + -20
Combine like terms: -10 + -20 = -30
-2x = -30
Divide each side by '-2'.
x = 15
Simplifying
x = 15</span>
