It is given that
a+b=20 -------------------- (1)
b+c=30 -----------------------(2)
We have to calculate
3 a + 4 b +7 c
Now multiplying equation(1 )by 3,we get
3 a+ 3 b=60 ----------------------------------(3)
and Multiplying equation( 2) by 4,we get
4 b + 4 c=120 -----------------------------------(4)
Adding expression (3) and (4),we get i.e left hand side of 3 to left hand side of 4 and right hand side of 3 to right hand side of 4.
3 a+ 3 b+ 4 b+ 4 c=60+120
Adding like terms, we get
3 a+ 7 b+ 4 c =180, Which is the required solution.
Your answer would be -15.41. If you ever need any other kind of help, just ask me.
7 is the answer because de is parallel to xy.
Im not 100% sure but im pretty sure you are right brother! God bless...Good luck!
Answer:
See below, there may be more than one answer
Step-by-step explanation:
4(3+1)+2 = 18
(4+2)(3)+1 = 19
(1)(2+3)(4) = 20
(1+2)(3+4) = 21