Mathematics
Grade-8
Easy
Question
The sum of two numbers is -4. The sum of 3 times the first number and 4 times the second number is -13. Find the numbers.
- 1, 4
- -3, -1
- -5, 1
- 3, 5
Hint:
Sum of two numbers = -4
Let the numbers be x and y
x + y = -4
3x + 4y = -13
The correct answer is: -3, -1
Sum of two numbers = -4
Let the numbers be x and y
x + y = -4…………………………. 1
3x + 4y = -13……………………… 2
From 1
x + y = -4
x = -4 – y
Substituting in 2nd equation,
3(-4 – y ) + 4y = -13
-12 – 3y + 4y = -13
-12 + y = -13
y = -1
Substituting y in 1st equation,
x + (-1) = -4
x = -4 + 1
x = -3
The correct answer is: -3, -1
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