The correct answer is: [A]: " x <span>< 12 " . __________________________________________________ Given: __________________________________________________ " 5(x + 5) </span><span>< 85 " ; Simplify/ solve for "x" ; __________________________________________________ Method 1) __________________________________________________
Note the "distributive property of multiplication" : __________________________________________________ a(b + c) = ab + ac ;
a(b – c) = ab – ac . __________________________________________________ So, take the "left-hand side" of the inequality; and expand: __________________________________________________ </span> → 5(x + 5) = (5*x) + (5*5) = 5x + 25 ; <span> Now, rewrite the inequality:
</span>→ 5x + 25 < 85 ;
Subtract "25" from each side of the inequality ;
→ 5x + 25 – 25 < 85 – 25 ;
to get: _______________________________________ → 5x < 60 ;
Divide each side of the inequality by "5" ;
→ 5x / 5 < 60 / 5 ;
→ x < 12 ; which is: Answer choice:[A]: " x < 12 " . _______________________________________
Method 2) _______________________________________ Given: _______________________________________ " 5(x + 5) < 85 " ; Simplify/ solve for "x" ; _______________________________________ Divide EACH SIDE of the equation by "5" ;
[5(x + 5) ] / 5 < 85 / 5 ;
to get:
→ x + 5 < 17 ;
Subtract "5" from EACH SIDE of the inequality:
→ x + 5 – 5 < 17 – 5 ;
to get:
→ x < 12 ; which is: Answer choice:[A]: " x < 12 " . _________________________________________________