Question

if a²+b²+c²=30,a+b+c=10 then value of a +bc+ac​

Answer 1

Answer:

$\small{\underline{\sf{\pink{Given:}}}}$

• a² + b² + c² = 30.
• a + b + c = 10.

$\small{\underline{\sf{\green{To\:Find:}}}}$

• ab + bc + ac = ?

$\small{\underline{\sf{\blue{Formula\:Used:arrow}}}}$

${\boxed{\rm{{(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2ab + 2bc + 2ca }}}$

$\small{\underline{\sf{\red{Solution:}}}}$

$\implies{{(10)}^{2} = 30 + 2ab+ 2bc + 2ca}$

$\implies{100 = 30 + 2(ab + bc + ca)}$

$\implies{100 - 30 = 2(ab + bc + ca)}$

$\implies{70 = 2(ab + bc + ac)}$

$\implies{2(ab + bc + ac) = 70}$

$\implies{ab + bc + ac = \frac{70}{2} }$

$\implies{ab + bc + ac = 35}$

➱The value of ab + bc + ac = 35.

Answer 2

Answer:

answer is 35

Step-by-step explanation:

squaring (a+ b+ c=10)

a^2+b^2+c^2 +2ab+ 2bc+ 2ac=100

30+2(ab+bc+ac) = 100

so, ab+bc+ac=35