Thread: algebra substitution method with no coefficient of 1

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I'm having trouble on number 25

I know how to use the substituition method if a variable has a coefficient of 1 or -1 but none of the coefficients here have that

can someone please show me how to do this.

You have to solve one of the equations for y, and it doesn't matter which one.
6x-7y=-4 (subtract 6x from both sides)
-7y=-6x-4 (divide everything by -7)
y=6x/7 + 4/7 Now you can substitute. Generally speaking Elimination would be a much easier way to solve this to avoid the fractions.