Question

Help !

The system
y= 2x-8
y=-3x+16

can be solved several ways. Student 1 wants to use subtraction. Student 2 wants to use substitution. Show how each student would do this. ​

Answer 1

Explanation:

student 1

y = 2x-8 ---(1)

y = -3x+16 ---(2)

(1) - (2)

(2x-8)-(-3x+16) = y-y

5x = 24

x = 4.8 ---(3)

sub (3) into (1) :

y = 2(4.8)-8

= 9.6-8

= 1.6

therefore, x = 4.8 and y = 1.6.

student 2

y = 2x-8 ---(1)

y = -3x+16 ---(2)

sub (1) into (2) :

2x-8 = -3x+16

5x = 24

x = 4.8 ---(3)

sub (3) into (2) :

y = -3(4.8)+16

= -14.4+16

= 1.6

therefore, x = 4.8 and y = 1.6.