Science

Math

Humanities

... and beyond

Socratic Meta
Featured Answers

Topics

How do you solve by substitution $4x-7y=10$ and $y= x-7$ ?

1 Answer

Jun 4, 2015

Given
[1] $color(white)("XXXX")$ $4x-7y = 10$
[2] $color(white)("XXXX")$ $y = x-7$

Using [2] substitute $(x-7)$ for $y$ in [1]
[3] $color(white)("XXXX")$ $4x - 7(x-7) = 10$

Simplifying
[4] $color(white)("XXXX")$ $-3x +49 = 10$
[5] $color(white)("XXXX")$ $x = 13$

Using [5] substitute $(13)$ for $y$ in [2]
[6] $color(white)("XXXX")$ $y = (13) -7$
[7] $color(white)("XXXX")$ $y= 6$

$(x,y)=(13,6)$

Related questions

See all questions in Systems Using Substitution

Impact of this question

2881 views around the world

You can reuse this answer
Creative Commons License