Grade 109 grade maths
if a+b =10 and a^2 + b^2 =58 find the value of a^3 +b^3
if a+b =10 and a^2 + b^2 =58 find the value of a^3 +b^3
3 Answers
SHAIK AASIF AHAMED
Hello student,
Please find the answer to your question below
a³ + b³ = (a + b) (a² - ab + b²)
= 10 (58 - ab)
But (a + b)² = a² + 2ab + b² = 58+2ab
also (a+b)2=10² = 100 since a+b=10
58+2ab=100
=> 2ab =100-58=42
=> ab = 21
=>a³ + b³ = (a + b) (a² - ab + b²)
= 10 (58 - ab)
=10*(58 - 21) = 370
Please find the answer to your question below
a³ + b³ = (a + b) (a² - ab + b²)
= 10 (58 - ab)
But (a + b)² = a² + 2ab + b² = 58+2ab
also (a+b)2=10² = 100 since a+b=10
58+2ab=100
=> 2ab =100-58=42
=> ab = 21
=>a³ + b³ = (a + b) (a² - ab + b²)
= 10 (58 - ab)
=10*(58 - 21) = 370
anu
(a+b)^2=a^2+2ab+b^2 10^2=58+2ab (given:a^2+b^2=58)2ab=100-58ab=42÷2=21 (bringing 2 from oppsite) (a+b)^3=a+b(a^2-ab+b^2) (its the equa.)(a+b)^3=10(58-21) =370
Saifa
If a+b=10 and a^2+b^2=58Then a^2+b^2=(a+b)^2-2.a.b→58=10^2-2.a.b→58=100-2.a.b→2.a.b=100-58→a.b= 42/2 =21a^3+b^3=(a+b)^3-3.a.b(a+b)=1000-630=-370 ans
Other Related Questions on 9 grade maths
What are the differences between similar triangles and congruent triangles?
What are the differences between similar triangles and congruent triangles?
9 grade maths
Last Activity: 0 Years ago
The L.C.M of the smallest 2 digit composite number and the smallest composite number is:
- (a) 12
- (b) 4
- (c) 20
- (d) 44
The L.C.M of the smallest 2 digit composite number and the smallest composite number is:
- (a) 12
- (b) 4
- (c) 20
- (d) 44
9 grade maths
Last Activity: 1 Year ago