Explanation:
It is given that,
The cost is $20 for the design and $1.50 to print each t-shirt.
The cost, y, to print x t-shirts is given by the linear equation:
y = 1.5x + 20 ....(1)
Let us assume we need to find the total cost when he print 10 tshirt.
Put x = 10 in equation (1)
y = 1.5(10) + 20
= 15 + 20
= $35
Hence, the net cost is 35 when he had to print 10 tshirts