• Mar 29th 2010, 08:43 PM
BeBeMala
if 3x+4x+35=21, then find the value of 2x+10?

a) 6
B)-2
c)-4
d)-6

a triangle with perimeter 40 has a short side x, a middle side of 7 less than twice the shorter and a long side of 7 more than the middle side. which equation can be used to solve for x?

a) 4x=40
b) 5x-7=40
c)4x-7=40
d)5x-14=40
• Mar 29th 2010, 09:05 PM
Anonymous1
Well...

$\displaystyle 3x+4x+35=21$

$\displaystyle 7x + 35 = 21$ Combine like terms

7$\displaystyle x = 21 - 35 = -14$ Subtract $\displaystyle 35$ from both sides

$\displaystyle x= \frac{-14}{7} = -2$ Divide both sides by $\displaystyle 7$

So $\displaystyle 2x+10$ is,

$\displaystyle 2(-2) + 10 = 6$
• Mar 29th 2010, 09:10 PM
Anonymous1
Perimeter = small side + middle side + long side

$\displaystyle 40 = [x] + [2x-7] + [7+(2x-7)]$

You finish this one...
• Mar 29th 2010, 09:18 PM
BeBeMala
Quote:

Originally Posted by Anonymous1
Perimeter = small side + middle side + long side

$\displaystyle 40 = [x] + [2x-7] + [7+(2x-7)]$

You finish this one...

i need to combine life term?
for example 5x-7=40 is the answer?
• Mar 29th 2010, 09:27 PM
Anonymous1
Correct. Do you understand now?