How do you solve #13A = 65 #?

2 Answers
Dec 12, 2015

Answer:

#color(blue)(A=5#

Explanation:

#13A=65#

#A=65/13#

#color(blue)(A=5#

Dec 12, 2015

Answer:

#A=65/13#

The explanation gives a very detailed introduction to the method for solving this type of question!

Explanation:

Given: #color(brown)(13A=65)#

#color(brown)("The objective is to get A on its own on one side of the equals sign")# #color(brown)("and everything else on the other.")#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("There three things that it is very important you remember:")#

#color(blue)("Point 1:")#
If we can change the 13 from 13A into the value of 1 we
would have #1xxA# which is the same as just #A#.

#color(blue)("Point 2:")#
What you do to one side of the equals you also do the other.
Consider 4=4. This we know to be true. But suppose we subtracted 1 from only the left side we would have #4-1!=4# but if we did this instead; #4-1=4-1# then both sides still have the same value.
#color(white)(xxxx)#
#color(blue)("Point 3")#
The same process applies to addition, multiplication, division squaring, taking square roots and so on!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#color(brown)("Changing the 13 into 1")#

Multiply both sides by #color(blue)(1/13)#

#color(blue)(1/13xxcolor(brown)( 13A = 65)xx1/13)#

giving:

#13/13xxA=65/13#

#1xxA=65/13#

But #1xxA# is the same as just #A# giving

#A=65/13#