Wednesday

April 16, 2014

April 16, 2014

Posted by **TO: Mathmate** on Monday, April 23, 2012 at 10:52pm.

Y=3x+1

Y=5x-3

Answer says x=-2 and y=7

Please explain steps. Thanks

math help - MathMate, Monday, April 23, 2012 at 10:25pm

Y=3x+1 ...(1)

Y=5x-3 ...(2)

By comparison of (1) and (2), we conclude that

3x+1=Y=5x-3

3x+1=5x-3

solve for x to get

2x=4

x=2

Put x=2 in (1) to get

Y=3(2)+1=7

Check:

put x=2 in (2) to get

Y=5*2-3=7

If your program gives x=-2 and y=7, there must be a typo somewhere. Check your post

- Math Help -
**Bosnian**, Monday, April 23, 2012 at 11:09pmy = 3 x + 1

y - 1 = 3 x Divide both sides by 3

( y - 1 ) / 3 = x

x = ( y - 1 ) / 3

y = 5 x - 3

y = 5 * ( y - 1 ) / 3 - 3

y = ( 5 / 3 ) * ( y - 1 ) - 3

y = 5 y / 3 - 5 / 3 - 3

y = 5 y / 3 - 5 / 3 - 9 / 3

y = 5 y / 3 - 14 / 3

y - 5 y / 3 = - 14 / 3

3 y / 3 - 5 y / 3 = - 14 / 3

- 2 / 3 y = - 14 / 3 Multiply both sides by - 3

2 y = 14 Divide both sides by 2

y = 14 / 2

y = 7

x = ( y - 1 ) / 3

x = ( 7 - 1 ) / 3

x = 6 / 3

x = 2

x = 2 , y = 7

Or very simply :

y = 3 x + 1

y = 5 x - 3

3 x + 1 = 5 x - 3

3 x - 5 x = - 3 - 1

- 2 x = - 4 Divide both sides by - 2

- 2 x / - 2 = - 4 / - 2

x = 2

y = 3 x + 1

y = 3 * 2 + 1 = 6 + 1 = 7

y = 5 x - 3

y = 5 * 2 - 3 = 10 - 3 = 7

x = 2 , y = 7

**Related Questions**

Math - how would you find the value of b and c using substitution? The equation ...

Grade 12 Math - how would you find the value of b and c using substitution? The ...

Microeconomics - 1. The utility function is given by: U=x+y and the budget line ...

Math (Algebra) - I sent my professor asked the pros and cons of each method, I ...

Substitution Method-Plz help - Use the Substitution method to solve the system ...

calculus - We're doing indefinite integrals using the substitution rule right ...

Geometry - Substitution Property of Equality: If a=20, then 5a= _____. The ...

Math - Calculate the integrals by partial fractions and using the indicated ...

Calculus 2 - Evalute the integral of x/(x^2+4)dx using u-substitution and then ...

Substitution Method!PLZ HELP 2222!! - y-2x=-5 3y-x=5 In the top equation: 1) y=...