Maria = x
Tom = y
Use substitution
x+y=30
2y=x
2y+y=30
3y=30
y=10
Tom is 10 years old.
x+y=30
x+10=30
x=20
Maria is 20 years old.
To get your answer you first subtract 10 from 128 which is 118.
-5 and 1/10
try to convert tomixed fraction
1=10/10 in this problem
-5=-50/10
add
-50/10-1/10=-51/10
another form is decimal form
-5 and 1/10
1/10=0.1
-5.1 is another answer
René Descartes was the person who created analytic geometry and the Cartesian coordinate system
