How many solutions does the equation 5x + 3x –4 = 10 have? Zero One Two Infinitely many
if you can't tell me right away, then lets solve this equatin.
Do you see any like terms on the left hand side of the equation ?
no
I will color the like terms in blue \(\large\color{black}{ \displaystyle \color{blue}{5x} + \color{blue}{3x} -4 = 10 }\)
Add the x 's. What is \(\normalsize\color{black}{ \displaystyle \color{blue}{5x+} \color{blue}{3x} }\) ?
8x
yes, so \(\large\color{black}{ \displaystyle \color{blue}{5x} + \color{blue}{3x} -4 = 10 }\) \(\large\color{black}{ \displaystyle \color{blue}{8x} -4 = 10 }\)
now, you have variables (x's ) and numbers (the -4 in this case) on left side and on right side you have a number. can you eliminate the variables for me?
lets add 4 to both sides \(\large\color{black}{ \displaystyle 8x-4 \color{darkgoldenrod}{\bf +4} = 10\color{darkgoldenrod}{\bf +4} }\)
what is -4+4 = ?
0
yes, and 10+4
is?
14
Yup !! \(\large\color{black}{ \displaystyle 8x-4 \color{darkgoldenrod}{\bf +4} = 10\color{darkgoldenrod}{\bf +4} }\) \(\large\color{black}{ \displaystyle 8x+0= 14 }\) so we now have just \(\large\color{black}{ \displaystyle 8 \times x = 14 }\)
by what do you divide on both sides, to solve for x (to isolate the x) ?
?
so is there only one posibiltity to make an equation?
or is there more?
\(\large\color{black}{ \displaystyle 8x= 14 }\) alright, I will tell you. We have to divide by 8 on both sides \(\large\color{black}{ \displaystyle 8x \color{magenta}{\div 8}= 14 \color{magenta}{\div 8} }\)
yes, correct there is only one solution
\(\large\color{black}{ \displaystyle 8x \color{magenta}{\div 8}= 14 \color{magenta}{\div 8} }\) \(\large\color{black}{ \displaystyle \cancel{8}x \color{magenta}{\div \cancel{8}}= 14 \color{magenta}{\div 8} }\) \(\large\color{black}{ \displaystyle x= 14 \color{magenta}{\div 8} }\)
x=14/8 x=7/4
and it is x=7/4
ok thanks for the help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!SolomonZelman
sure
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