Suppose that we want to solve the equation
This equation has a fractional coefficient of The term means that is being multiplied by and divided by
We can solve this problem by applying the multiplication principle, twice. First, we multiply both sides by to get rid of the fraction:
Then, we divide both sides by to isolate
Solve for if
First, we multiply both sides by to get rid of the fraction:
Then, we divide both sides of the equation by to isolate
If $\dfrac 4 3 x = 8$, then $x =$
a
|
$3$ |
b
|
$6$ |
c
|
$\dfrac{3}{32}$ |
d
|
$\dfrac{1}{6}$ |
e
|
$\dfrac{32}{3}$ |
If $\dfrac 2 5 x = 4$, then $x =$
a
|
$10$ |
b
|
$18$ |
c
|
$\dfrac 5 8$ |
d
|
$\dfrac 3 7$ |
e
|
$\dfrac 8 5$ |
When solving equations with fractional coefficients, there is a shortcut! We can complete division and multiplication in a single step by multiplying both sides of the equation by the reciprocal of the fractional coefficient.
For example, to solve the equation we first express the fraction as a coefficient:
The fractional coefficient is , and its reciprocal is Because the product of a fraction and its reciprocal is equal to we can multiply both sides of the equation by the reciprocal to isolate
If , then what is the value of
We multiply both sides of the equation by the reciprocal of which is This gives
If $-\dfrac{12}{5}v = 7,$ then $v=$
a
|
$-\dfrac{35}{12}$ |
b
|
$-\dfrac{57}{12}$ |
c
|
$-\dfrac{84}{5}$ |
d
|
$-\dfrac{75}{12}$ |
e
|
$-\dfrac{7}{5}$ |
If $\dfrac{7w}{17}=-7$, then $w =$
a
|
$-7$ |
b
|
$-\dfrac{17}{7}$ |
c
|
$17$ |
d
|
$-17$ |
e
|
$-\dfrac{7}{17}$ |
Solve the equation
First, we isolate the fractional term by adding to both sides:
The fractional coefficient is so we multiply by its reciprocal This gives
If $\dfrac {5z} 3 + \dfrac 1 2= 1$, then $z =$
a
|
$\dfrac 6 {10} $ |
b
|
$3$ |
c
|
$\dfrac 3 {10} $ |
d
|
$\dfrac 9 2 $ |
e
|
$2$ |
If $\dfrac {7y} 2- 3 = 11$, then $y =$
a
|
$14$ |
b
|
$7$ |
c
|
$4$ |
d
|
$\dfrac {16} {7}$ |
e
|
$\dfrac {22} {7}$ |