Question 26250
<pre>Could I have the answer for this question please. 
7-3(5t-10)=67 
is the answer t=6 or t=2
when calculating do I use -3x15 or 3x15. Could you give me some algebra tips
for this. Thanks 
<font face = "lucida console" size = 4><b>
The first one!  When removing parentheses by the distributive rule,
always take the sign in front of the multiplier along with the multiplier.

7 - 3(5t-10) = 67

Write down the 7

7

Then taking the sign with the 3, multiply -3 by 5t and get -15t.  Write that
down, so you have

7 - 15t

Now multiply the -3 by the -10, getting +30, so write than next. Now you have

7 - 15t + 30

Then copy " = 67 "

7 - 15t + 30 = 67 

Combine the 7 with the 30 and get 37

    37 - 15t = 67

Subtract 37 from both sides and get

        -15t = 30

Then divide both sides by -15

       -15t     30
      覧覧覧 = 覧覧
       -15     -15

           t = -2

Edwin
AnlytcPhil@aol.com</pre>