$3n+9n=-2(7-4n)-(1+n)\\\\\mathrm{Add\:similar\:elements:}\:3n+9n=12n\\\\12n=-2\left(7-4n\right)-\left(1+n\right)\\\\\mathrm{Expand\:}-2\left(7-4n\right)-\left(1+n\right):\quad 7n-15\\\\12n=7n-15\\\\\mathrm{Subtract\:}7n\mathrm{\:from\:both\:sides}\\\\12n-7n=7n-15-7n\\\\Simplify\\\\5n=-15\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\\\frac{5n}{5}=\frac{-15}{5}\\\\Simplify\\\\n=-3$

6 0

4 years ago

Read 2 more answers

Solve the equation by finding square roots. To start, remember to isolate x^2. Equation= x^2+4=20

prohojiy [21]

Get the equation simplified. Subtract 4 by each side.
20-4= 16
and the square root of 16, is 4.
Plug it in to check.
(4)^2+4=20
16+4=20
20=20

Ultimately your final answer is X=4

4 0

3 years ago