Solve by the substitution method 15x minus 20y equals 1 15y equals -1 plus 10x?

Answer 1

equation (1) 15x-20y=1

equation (2) 15y=-1+10x

to slove by substitution:

• rearrange one equation to make one of the variables the subject
• substitute it into the other equation
• solve for the variable
• use value to solve for other variable
• (optional) use second variable in other equation to ensure first answer it correct

rearrange (1): x=(1+20y)/15

substitute in (2): 15y=-1+10(1+20y)/15

15y=13.3-0.3

y=0.87

substitute in (1): 15x-20(0.87)=1

15x=18.3

x=1.2

check