The last one on the bottom
7 (2x +5 -3y)
Answer:
-8x-6 or -8x+-6.
Step-by-step explanation:
Of all the choices presented above, only letter D. 13 does not satisfy the inequality as the number should be higher than 13. Out of the choices that satisfy the inequality, only letter C. makes sense. Letter A and B satisfy the inequality but do not makes sense as this represent the ages of very old people already which are not capable of playing the sports.
Thus, the answer is letter A. 102 and letter B. 96.
Equations b and d have the same solutions, because if you multiply both sides of b by 2 and invert the constants you'll have equation d:
b: x - 3 = 5x + 4
b*2: 2x - 6 = 10x + 8
Move -6 and +8 to the other side: 2x -8 = 10x +6 <-- this is equation d
Similarly, starting from equation a, you can obtain equation e by multiplying both sides by 2 and equation f by dividing both sides by 10.
Equation c has nothing in common with the others.