A+E+F=0 50A+B +55E+55F=0
985A+38B+C +1200E+1200F=0
9540A+529B+26C+D+12960E+12960F=0
45360A+3192B+217C+14D+69120E+69120F =0
84672A+7056B+588C+49D+145152E+14515 2F=9

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Evaluate this using ! 0.25^2 x 2.4 + 0.25 x 2.4^2 − 0.25 x 2.4 x 0.65

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of