Zwelibanzi and Jessica are friends. Zwelibanzi takes Jessica’s civil technology test paper and will not tell her what her mark is. He knows Jessica dislikes word problems so he decides to tease her. Zwelibanzi says: : I have 12 marks more than you do and the sum of both our marks are equal to 148. What are our marks?

80 and 68

Step-by-step explanation:

Jessica's marks = x

Zwelibanzi's marks = y

We get following equations as per given:

Sum up the two equations to substitute x:

And finding the value of x:

Marks are: 80 and 68

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!

answer: what in the world is this

step-by-step explanation: