Let A and B represent the number of hours that plans A and B last, respectively. Then the problem statement tells you
7A +9B = 12
5A +3B = 6
There are many ways this set of equations can be solved. I find it fairly simple to use a graphing calculator. The one shown tells me the workouts are each 3/4 of an hour.
Plan A lasts 45 minutes (3/4 hour)
Plan B lasts 45 minutes (3/4 hour)
Answer:
-1/5m+-4/5
Step-by-step explanation:
ez pz
Answer:
14.11
Step-by-step explanation:
24 divided by 1.7
Answer:
EF = 20 cm
Step-by-step explanation:
Here, we want to find the length of EF
To do this, we use the principle of similar triangles
The similar triangles we are considering here will be ;
FEA and FBD
when two triangles are similar, the ratio of their corresponding sides are equal
Let us calculate DC first
we can use Pythagoras’ theorem here and it is that the square of the hypotenuse equals the sum of the square of the two other sides
Using the triangle EDC
15^2 = 12^2 + DC^2
DC^2 = 225-144
DC^2 = 81
DC = 9
So the entire length of BD is 9 + 12 = 21 cm
Thus, we have it that;
Let EF be x
so DF = 15 + x
Hence;
BD/DF = AE/EF
21/15+x = 12/x
21x = 12(15 + x)
21x = 180 + 12x
21x-12x = 180
9x = 180
x = 180/9
x = 20 cm
EF = 20 cm