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How to solve for y in #5x-y=33# and #7x+y=51#?

Answer 1

Savannah Anderson

#y=5x-33# and #y=-7x+51#.

First Equation:

#5x-y=33#

Subtract #5x# from both sides.

#-y=33-5x#

Multiply both sides by #-1#.

#y=-33+5x#

Rearrange.

#y=5x-33#

Second Equation:

#7x+y=51#

Substitute the #y# from the first equation

#7x+(5x-33)=51->12x-33=51#

Add #33# to both sides, and then divide by #12#

#12x=84->x=7#

Now put this into the equation for #y#

#y=5x-33->y=5*7-33=35-33->y=2#

Answer : #x=7,y=2#

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Answer 2

Abigail Allen

To solve for (y) in the system of equations (5x - y = 33) and (7x + y = 51), first solve one equation for (y) and then substitute that expression into the other equation. Then solve for (x). Once you find the value of (x), substitute it back into one of the original equations to find the value of (y).

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.