3a+5b+2c=?
a+b=15
b+c=14
5b=3b,2b

Step-by-step explanation:

please check you typing 5b = 3b, 2b

73

Step-by-step explanation:

3a + 5b + 2c = ?

Given:

a + b = 15

b + c = 14

now express in terms of b

a = 15 - b    equation (i)

c = 14 - b     equation (ii)

3a + 5b + 2c

substitute the values

3(15 - b) + 5b + 2(14 - b)

45 - 3b + 5b + 28 - 2b

add or subtract like terms

73 + 5b - 5b

plus 5b and minus 5b gets cancel

73

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour

-3.5 degrees per hour

step-by-step explanation:

find the unit rate:

-12   1/4 degrees           12.25 degrees

= - = -3.5 degrees per hour

      3   1/2 hours               3.5 hours