the sum of two numbers is 99, the difference of those two numbers is 9. what are the two numbers???
3 answers
I believe 54 and 45 would work.
yep it does ty...it was an easy problem i just didn't feel like solving it so thnx =]
But no work was shown. Was this just trial and error, or was math used?
"the sum of two numbers is 99"
x + y = 99
"the difference of those two numbers is 9."
x - y = 9
Solve one equation for either variable.
x - y = 9
x = y + 9
now substitute this value for x into the other equation.
x + y = 99
(y + 9) + y = 99
2y + 9 = 99
2y = 90
y = 45
Now substitute that numeric value for y into one of the original equations to find the numeric value of x.
x + y = 99
x + 45 = 99
x = 54
"the sum of two numbers is 99"
x + y = 99
"the difference of those two numbers is 9."
x - y = 9
Solve one equation for either variable.
x - y = 9
x = y + 9
now substitute this value for x into the other equation.
x + y = 99
(y + 9) + y = 99
2y + 9 = 99
2y = 90
y = 45
Now substitute that numeric value for y into one of the original equations to find the numeric value of x.
x + y = 99
x + 45 = 99
x = 54
1 answer