mathdad
Full Member
- Joined
- Apr 24, 2015
- Messages
- 737
There are two numbers whose sum is 53. Three times the smaller number is equal to 19 more than the larger number. What are the numbers?
Set up:
Let x = large number
Let y = small number
x + y = 53...Equation A
3y = x + 19....Equation B
x + y = 53
y = 53 - x...Plug into B.
3(53 - x) = x + 19
159 - 3x = x + 19
-3x - x = 19 - 159
-4x = -140
x = -140/-4
x = 35...Plug into A or B.
I will use A.
35 + y = 53
y = 53 - 35
y = 18.
The numbers are 18 and 35.
Yes?
Set up:
Let x = large number
Let y = small number
x + y = 53...Equation A
3y = x + 19....Equation B
x + y = 53
y = 53 - x...Plug into B.
3(53 - x) = x + 19
159 - 3x = x + 19
-3x - x = 19 - 159
-4x = -140
x = -140/-4
x = 35...Plug into A or B.
I will use A.
35 + y = 53
y = 53 - 35
y = 18.
The numbers are 18 and 35.
Yes?