Inequality problem

Question

An integrated circuit chip is designed to operate in a temperature range

of -3 C to 87 C. This gives us -3 < (or equal to) 5/9(F - 32) < (or equal to)

87 where F is measured in degrees Fahrenheit.

Solve for F to get an inequality that gives the operating temperature

range in degrees Fahrenheit.

A) 26.6 F< (EQUAL TO) X < (EQUAL TO) 158.6 F

B) 26.6 F < (EQUAL TO) X < (EQUAL TO) 168.6 F

C) 26.6 F < (EQUAL TO) X < (EQUAL TO) 178.6 F

D) 26.6 F < (EQUAL TO) X < (EQUAL TO) 188.6 F

E) 26.6 F < (EQUAL TO) X < (EQUAL TO) 198.6 F

Answer 1

F = 9/5*C + 32

-3 < C < 87 <--- given

-27 < 9C < 783 -- multiplies by 9

-27/5 < (9/5)C < 783/5 <--- divides by 5

32 - 27/5 < (9/5)C + 32 < = 783/5 + 32 <--- adds 32

(160-27)/5 < F < (783 + 160)/5 <--- common denominator is 5; conversion to fahrenheit is complete

133/5 < F < 943/5

26.6 < F < 188.6

option D