x-y=4 2x+3y=10 find: 3x+2y
FIrst you need to figure out what either x or y equals with one of the equations. It doesn't matter which, because they are dependent on eachother and will both give the same number at the end.
I chose to go with the first equation, because it was simplier, which makes it easier to find the first variable. Again you can solve for either x or y first, I chose x
x-y=4
becomes
x=4+y
now we can plug this x value into the second equation of 2x+3y=10 to find
2(4+y)+3y=10
8+2y+3y=10
8+5y=10
solving for y
5y=2
y=2/5
Now we can plug this y value into the first equation to get an actual value of x
x-(2/5)=4
x=4+2/5
x=22/5
since we now have both x and y values, x=22/5 y=2/5, we can plug them into the 3rd equation to find what it equals
3(x)+2(y)=??
3(22/5)+2(2/5)=??
66/5+4/5=??
70/5=14
