WHY must the same operation be performed on both sides of an equation?
1 answer:
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Here's what I mean when I write <em>x/</em><em>2</em><em> </em><em>JUST </em><em>IN </em><em>CASE.</em>
а.
Let the total number of pencils be x, then this implies that Maggie received <em>x/</em>2 pencils from Katie. Maggie keeps 5 and give the rest to Jamil, this means
that Jamil receives
<em>x/</em>2-5 pencils.
b. Expression of pencils given to Jamil is: <em>x/</em>2-5
Substitute <em>x</em><em>=</em><em>1</em><em>6</em><em> </em>in this expression: <em>x/</em>2-5
Simplify and evaluate: = 8-5= 3
Maggie gives 3 pencils to Jamil.
c. Expression of pencils given to Jamil is: x/2-5 to
Equate this expression with 1 to form an equation and solve for <em>x</em> all, the total
number of pencils if Jamil received 1 pencil:
<em>x/</em>2 - 5 = 1
Solve for x:
<em>x</em> = 2(1+ 5)
Evaluate:
<em>x</em> = 2(6) = 12
Katie had 12 pencils if Jamil received 1 pencil.
RESULT
a. Expression of number of pencils given to Jamil is <em>x</em>/2-5, where x is total number of pencils.
b. Maggie gives 3 pencils to Jamil.
c. Katie had 12 pencils if Jamil received 1 pencil.
Get everything on one side: 
. Now we can factor to find the solutions. What we ask ourselves here is "What 2 numbers will add to be +4 and multiply to be -21?" +7 and -3 work because 7-3 = 4 and 7 * -3 = -21. So our factors are (x+7)(x-3). Our solutions, however, are found using the Zero Product Property. If x + 7 = 0, then x = -7. If x - 3 = 0, then x = 3. So our solutions are x = -7 and x = 3.