Answer:y= -4
Step-by-step explanation:
1 Solve for xx in 7x-4y=-127x−4y=−12.
x=\frac{4(y-3)}{7}
x=
7
4(y−3)
2 Substitute x=\frac{4(y-3)}{7}x=
7
4(y−3)
into 9x-4y=-209x−4y=−20.
\frac{36(y-3)}{7}-4y=-20
7
36(y−3)
−4y=−20
3 Solve for yy in \frac{36(y-3)}{7}-4y=-20
7
36(y−3)
−4y=−20.
y=-4
y=−4
4 Substitute y=-4y=−4 into x=\frac{4(y-3)}{7}x=
7
4(y−3)
.
x=-4
x=−4
5 Therefore,
\begin{aligned}&x=-4\\&y=-4\end{aligned}
x=−4
y=−4
You solve it just like you would with an equation.
Answer:
x = 18 y = 10
Step-by-step explanation:
let the first number be x
let the second number be y
x = y + 8..... equation 1
2x + y = 46.... equation 2
x is the larger number
y is the smaller number.
Rearrange the equation and add equation 1 to equation 2.
x - y = 8
+ 2x + y = 46
-------------------
3x + 0 = 54
3x = 54
divide both sides by 3
x = 54/3
x = 18
Substitute x = 18 into equation 1
x = y + 8
18 = y + 8
collect like terms
y = 18-8
y = 10
Markup = $4
b) markup as a percentage of cost is 33.3%
Step-by-step explanation:
Markup
markup = selling price - cost
= $13 - 9
... markup = $3
Markup as a Percentage of Cost
To find the percent markup, divide the markup by the reference value and multiply the ratio by 100%. The reference value for markup is usually cost price, but sometimes may be selling price.
... markup / cost × 100% = 3/9×100% = 33 1/3% ≈ 33.3%
