The value of x and y in the equation -5x + 8y = -21 and 3x - 4y = 15 are 9 and 4 respectively.
<h3>What is an equation?</h3>
An equation is the statement that illustrates that the variables given. In this case, two or more components are taken into consideration to describe the scenario. It is vital to note that an equation is a mathematical statement which is made up of two expressions that are connected by an equal sign.
The equation is given as:
-5x + 8y = -21
3x - 4y = 15
Multiply equation i by 3
Multiply equation ii by 5
-15x + 24y = -63
15x - 20y = 75
Add both equations
4y = 12
Divide
y = 12/4
y = 3
From 3x - 4y = 15
3x - 4(3) = 15
3x - 12 = 15
Collect like terms
3x = 12 + 15
3x = 27
Divide
x = 27/3
x = 9
Therefore, x = 9 and y = 4.
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Answer:
x= 60
Step-by-step explanation:
Total number of people= x
Let the number of children, men and women be c, m and w respectively.
c= ⅓x -----(1)
m= ⅗w -----(2)
w= c +5 -----(3)
Substitute (1) into (3):
w= ⅓x +5 ----(4)
Substitute (4) into (2):
m= ⅗(⅓x +5)
m= ⅕x +3 -----(5)
Since the total number of people is x,
c +m +w= x -----(6)
Substitute (1), (5) and (4) into (6):
⅓x +⅕x +3 +⅓x +5= x
⅔x +⅕x +8= x
![\frac{10}{15} x + \frac{3}{15} x + 8 = x](https://tex.z-dn.net/?f=%20%5Cfrac%7B10%7D%7B15%7D%20x%20%2B%20%20%5Cfrac%7B3%7D%7B15%7D%20x%20%2B%208%20%3D%20x)
![\frac{13}{15} x + 8 = x](https://tex.z-dn.net/?f=%20%5Cfrac%7B13%7D%7B15%7D%20x%20%2B%208%20%3D%20%20x)
![x - \frac{13}{15} x = 8](https://tex.z-dn.net/?f=x%20-%20%20%5Cfrac%7B13%7D%7B15%7D%20x%20%3D%208)
![\frac{2}{15} x = 8](https://tex.z-dn.net/?f=%20%5Cfrac%7B2%7D%7B15%7D%20x%20%3D%208)
![x = 8 \div \frac{2}{15}](https://tex.z-dn.net/?f=x%20%3D%208%20%5Cdiv%20%20%5Cfrac%7B2%7D%7B15%7D%20)
![x = 8 \times \frac{15}{2}](https://tex.z-dn.net/?f=x%20%3D%208%20%5Ctimes%20%20%5Cfrac%7B15%7D%7B2%7D%20)
x= 4(15)
x= 60
Answer:
<u>There are 3.48 cups of water in 4 cups of skim milk</u>
Step-by-step explanation:
Skim milk has 87% water = 0.87
How much water is in 4 cups of skim milk?
Amount of water = Number of cups * Percentage of water
Amount of water = 4 * 0.87
Amount of water = 3.48 cups
<u>There are 3.48 cups of water in 4 cups of skim milk</u>
Answer:
58°
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the two remote interior angles.
m∠A + m∠C = measure of exterior angle at B
2x + 2 + 54 = 4x
2x + 56 = 4x
2x = 56
x = 28
m∠A = 2x + 2 = 2(28) + 2 = 56 + 2 = 58°
Answer:
x=1
Step-by-step explanation:
3/2+1/2x=2x
Multiply each side by 2 to get rid of the fractions
2(3/2+1/2x)=2x*2
3+x = 4x
Subtract x from each side
3+x-x = 4x-x
3 = 3x
Divide each side by 3
3/3 = 3x/3
1 =x