Using the numbers 1, 2, 3, and 4 (ONLY ONCE), and the operations of adding, subtracting, multiplying, dividing, and the use of parenthesis, write an expression that evaluates to 21.

Step-by-step explanation:

=(4+3)×(2+1)

=7×3

=21

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x

correct answer is infinitely many solutions

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

solving the above equation:

4x + 6 = -4 +4x +10

combining like terms

4x -4x = -4+10-6

0=0

since both sides are 0=0, we end up into true statement it means it has infinite many solutions.

so correct answer is infinitely many solutions