Question

At Elisa's printing company llc there are two kinds of printing presses: model a which can print 70 books per day and model b which witch can print 55 books per day. Company owns 14 total Printing Presse sand this allows 905 books per day. How many of each type of press do they have..

Answer 1

70a + 55b = 905
a + b = 14
55a + 55b = 770

(70a-55a) + (55b-55b) = 905 - 770
15a = 135
a = 9

a + b = 14
9 + b = 14
b = 5