Answer: (-5,1)
Step-by-step explanation:
−2.5x+y=13.5
−2.5x+y+2.5x=13.5+2.5x(Add 2.5x to both sides)
y=2.5x+13.5
Step: Substitute
5x+13.5 and 2.25x−y=−12.25:
2.25x−y=−12.25
2.25x−(2.5x+13.5)=−12.25
−0.25x−13.5=−12.25(Simplify both sides of the equation)
−0.25x−13.5+13.5=−12.25+13.5(Add 13.5 to both sides)
−0.25x=1.25
−0.25=1.25−0.25(Divide both sides by -0.25)
x=−5
Step: Substitute−5forxiny=2.5x+13.5:
y=2.5x+13.5
y=(2.5)(−5)+13.5
y=1(Simplify both sides of the equation)
Answer:
x = -4, y = 3.5
Step-by-step explanation:
-2.5x + y = 13.5 ------ (1)
2.25x - y = -12.25 ---(2)
you can substitute (1) into (2) or vice versa
We are going to substitute (2) into (1)
but first we have to rewrite it in terms of x or y
Lets do y
from (2), (after subtracting -2.25x from both sides), y = 12.25 + 2.25x ----(3)
plug in (3) into (1)
-2.5x + (12.25 + 2.25x) = 13.5
-2.5x + 12.25 + 2.25x = 13.5
-2.5x + 2.25x = 13.5 - 12.5
-0.25x = 1
x = -(1/.25)
x = -4
Now we have x
We already used (2), lets plug in x = -4 into (1)
-2.5(-4) + y = 13.5
10 + y = 13.5
y = 13.5 - 10
y = 3.5
