Question

If the replacement set is a set of natural numbers then find the sum of elements of solution set of 12 - 4x ≥ -9

• A. 6
• B. 15
• C. 3
• D. 10

Answer 1

The correct option is B 15

$12-4x\ge -9$

$12+9\ge 4x$

$21\ge 4x$

$\frac{21}{4}\ge x$

$5\frac{1}{4}\ge x$

$x$ = {1, 2, 3, 4, 5}
Sum of elements = 1 + 2 + 3 + 4 + 5 = 15

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