The total units of stationery he has would be 55 approximately.
<h3>What is a system of equations?</h3>
A system of equations is two or more equations that can be solved to get a unique solution. the power of the equation must be in one degree.
David keeps a range of stationery in his study.
Let the pencil is represented by x.
Let the erasers be represented by y.
Let the pens be represented by z.
Let n be the stationery.
5/7 of his stationery consists of pencils.
x = 5/7 n
1/6 of the remaining stationery consists of erasers.
y = 1/6 n
There are 20 pens in his study.
z = 20
The total stationery
X + y + z
5/7 n + 1/6 n + 20 = n
20 = n -23/ 36 n
20 = 13 / 36 n
n = 55.38
Therefore, the total units of stationery he has would be 55 approximately.
Learn more about equations here;
brainly.com/question/10413253
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