Use substitution
Plug in 5x for y
5x = 2x - 15
Subtract 2x
3x = -15
Divide by 3
x = -5, y = -25
Solution: (-5, -25)
Step-by-step explanation:
The dimensions of the rectangle are two unknowns: The length "l" and the width "w"
The perimeter of a rectangle is found as P = 2*l + 2*w
We also know that the length is 5cm more than twice the width. l = 2*w + 5
These two equations gives us a system of linear equations.
P = 2*l + 2*w
l = 2*w + 5
We can use substitution to replace the "l" in the first equation with 2*w + 5
P = 2*(2*w + 5) + 2*w
P = 4*w + 10 + 2*w
P = 6*w + 10
we know the perimeter is 70
70 = 6* w + 10
subtract 10 from both sides
60 = 6* w
w = 10
Now that we know the width, we can find the length by substituting 10 for "w" in the second equation.
l = 2* 10 + 5
l = 20 +5
l = 25
the dimentions of the rectangle are 25cm x 10 cm
Answer:
x=4
Step-by-step explanation:
7x - 9 = 19
add 9 to both sides
7x = 28
divide by 7
x = 4
