If a^2+b^2=13 and ab =6 find the value of
(i)(2a+2b)
(ii)(2a-2b)

I)

II)

Step-by-step explanation:

We are given that:

I)

Recall the perfect square trinomial pattern:

Rewrite:

Substitute:

Evaluate:

Take the square root of both sides:

Hence:

Therefore:

II)

Likewise:

Substitute:

Solve:

In conclusion:

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation:

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb