Question

the price of 2tables &3 chairs is 340 but table cost is 20 more than the chair find the cost of each

Answer 1

Let us assume that a table is represented by x and chair by y.
The equation that evolves is 2x + 3y = 340
Since the cost of table is 20 more than that of a chair, we can replace x (table) with y + 20 in the above equation.
Therefore, when we rewrite this equation, we get:
2(y + 20) + 3y = 340
2y + 40 + 3y = 340 (upon expanding the first term)
5y + 40 = 340
5y = 340 - 40
5y = 300
y = 300 / 5
y = 60 (remember, y = chair)
Therefore, the cost of the chair is 60
Since, the cost of the table is 20 more than that of the chair, the cost of the table is 60 + 20 = 80.

Answer: The cost of the table is 80 and that of the chair is 60

Proof:
2 tables = 2 x 80 = 160
3 chairs = 3 x 60 = 180

2 tables + 3 chairs = 340
(2 x 80) + (3 x 60) = 340
160 + 180 = 340
340 = 340