Question

if ab is equal to 5 and a minus b is equal to 2 then find the value of a cube minus b cube​

Answer 1

Answer:

Step-by-step explanation:

ab=5

a-b=2

then cubing both sides in a-b=2. We get

(a-b)^3=2^3

a^3-b^3-3ab(a-b)=8

Putting values of ab and a-b we get

a^3-b^3-3×5(2)=8

a^3-b^3-30=8

a^3-b^3=8+30=30

a^3-b^3=38

Answer 2

Answer:

Hello Dear User__________

Here is Your Answer...!!

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Explanation:

$Given \ (a-b)=2 \ and \ ab=5\\\\we \ have \ to \ find \ a^{3} -b^{3}\\\\First \ just \ get \ square \ of \ (a-b)\\\\(a-b)^{2}=(2)^{2}\\\\a^{2}+ b^{2}-2ab=4\\\\ a^{2}+ b^{2}=4+10=14\\\\ we \ know \ formula \ a^{3} -b^{3}=(a-b)(a^{2}+ b^{2}+ab)\\\\a^{3} -b^{3}=(2)(14+5)\\\\a^{3} -b^{3}=2 \times 19\\\\a^{3} -b^{3}=38$

Hope it is clear to you.