Question

solve by substitution method
0.05x-0.01y=2.6
0.26x+0.18y=22.8

Answer 1

usually easier to work with whole numbers so start by getting rid of the fraction
multiply by 100

Answer 2

5x-y=26
26x+18y=228

Answer 3

to solve by substitution express one variable in terms of the other then use in the second equation.
you will have one equation with one variable.
solve for this variable.
use this value in the original to find the value of the other variable.

Answer 4

i dont understand how to do that

Answer 5

using the first equation
5x - y = 260
y = 5x -260
using this in the second equation
26 x + 18 (5x - 260) = 2280
can you continue

Answer 6

116x-4680=2280

Answer 7

keep going

Answer 8

x=60

Answer 9

you have x now find y

Answer 10

by pluggin in 60 to 5x-y=260?

Answer 11

yes

Answer 12

y=-40

Answer 13

watch your sign

Answer 14

its a negative isnt it?

Answer 15

y = 5x -260
= 5*60 -260 =300- 260 = 40
y = 40

Answer 16

5x60+y=260
300+y=260 subtract -300
y=-40

Answer 17

5x-y = 260

Answer 18

which is correct

Answer 19

look at the original

Answer 20

ok so we have to swtich it and it is a postive

Answer 21

the correct answer is 40

Answer 22

x = 60 and y = 40
always good practice to check your solution in the original

Answer 23

ok thanks

Answer 24

plug these values in the second equation to check

Answer 25

here is a review of the steps
1. pick a variable and find the expression for that variable using one of the equations
2. use this expression in the other equation.
3. solve for only variable in this equation
4. use this value to find the value of the other variable.
5. check your solution in either of the original equation
any questions?