Your answer you need is D
Answer:
{x,y} = {3/7,-43/7}
Step-by-step explanation:
System of Linear Equations entered :
[1] x + 3y = -18
[2] -x + 4y = -25
Graphic Representation of the Equations :
3y + x = -18 4y - x = -25
Solve by Substitution :
// Solve equation [1] for the variable x
[1] x = -3y - 18
// Plug this in for variable x in equation [2]
[2] -(-3y-18) + 4y = -25
[2] 7y = -43
// Solve equation [2] for the variable y
[2] 7y = - 43
[2] y = - 43/7
// By now we know this much :
x = -3y-18
y = -43/7
// Use the y value to solve for x
x = -3(-43/7)-18 = 3/7
Solution :
{x,y} = {3/7,-43/7}
Dacá 800 este 100% atunci 25% va fi 800/4 = 200 lei
deci resultá cá obiectul dupá reducere va costa 800-200 = 600 de lei
sper sá-ti fie de folos
succes
So I think you should set up an equation like this: 14.95x+16.88y=131.18 , x+y=8
so x=8-y, plug this into the original equation:
14.95(8-y)+16.88y=131.18
Evaluate: 119.60-14.95y+16.88y=131.18
Combine like terms: 119.60+1.93y=131.18
Subtract 119.60 from both sides. You get: 1.93y=11.58
Divide both sides by 1.93. You get y=6
Plug into second equation: x+y=8 ---> x+6=8 and solve for x. x=2
Christine bought 2 video games and 6 CDs. 14.95(2)+16.88(6)=131.18
I think this is a function..
