Answer:
12
Step-by-step explanation:
Givens
Harpreet = x + 3
Sukhpreet = x
Komalpreet = 2*(x + 3)
Average Age = 15
Equation
[(x + 3) + x + 2*(x + 3) ] / 3 = 15 Multiply both sides by 3
Solution
3 [(x + 3) + x + 2*(x + 3) ] / 3 = 15 * 3 Combine
[(x + 3) + x + 2*(x + 3) ] = 45 Remove the brackets
x + 3 + x + 2x + 6 = 45 Combine like terms
4x + 9 = 45 Subtract 9 from both sides
4x + 9 - 9 = 45 - 9 Combine
4x = 36 Divide by 4
4x/4 = 36/4
x = 9
Answer
Harpreet is x+ 3 = 9 + 3 = 12
Answer:
x + 7у = 23 3х + 14у = 48
Step-by-step explanation:
x + 7у = 23 3х + 14у = 48
You're trying to find constants

such that

. Equivalently, you're looking for the least-square solution to the following matrix equation.

To solve

, multiply both sides by the transpose of

, which introduces an invertible square matrix on the LHS.

Computing this, you'd find that

which means the first choice is correct.
The expression re-written: 3(2) - 4(3)
First, we multiply (PEMDAS)
3 * 2 = 6
4 * 3 = 12
6 - 12 = -6
Answer: - 6