Your last three posts are basically the same type of questions.
I will do this one for you, then you follow that procedure to do the others, ok?
The object is to have the coefficients of either the x or the y to be the same or opposite, so that you can either subtract or add the two equations.
This is based on the concept that by multiplying or dividing each side of an equation by the same number, the equation does not change.
I will go for the x's
#1 times 2: ---> 6x - 10y = 14
#2 times 3: ---> 6x + 9y = 90
subtract them
-19y = -76
divide by -19
y = 4
sub that back into either of the two original equations ....
y = 4 into #2
2x + 3(4) = 30
2x = 30-12
2x = 18
x = 9
check by using those values in the equation that was not used in the second part.
#1 :
Left Side = 3x - 5y
= 3(9) - 5(4)
= 27-20
= 7
= Right Side
So my solution is correct.
x = 9, y = 4
Solve by the linear combination method (with or without multiplication).
3x-5y = 7
2x + 3y = 30
1 answer