2x² - 128
2(x² - 64), but (x² - 64) = x² - 8² (difference of 2 squares),[a²-b²=(a-b)(a+b)]
2(x² - 64) = 2(x² - 8²) = 2(x-8)(x+8)
ANSWER
x=27
EXPLANATION
The two triangles are similar so the corresponding sides are equal.


Cross multiply to get;

Expand:
65x=39x+702
Group similar terms:
65x-39x=702
Simplify
26x=102
Divide both sides by 26,
x=702/26
x=27
Answer:
Nick needs to buy 3 packs.
Step-by-step explanation:
If Nick buys 3 packs he will have 18 cards. If he uses 15 of them he will have 3 left over. If he only bought 2 packs he would be 3 cards short of the amount he really needed.