Given:
Total savings = $400
Ratio of savings of Blake and Josh = 3:1
To find:
The saving of each.
Solution:
Let the savings of Blake and Josh are 3x and x respectively.
According to the question,


Divide both sides by 4.

Now,
Savings of Blake = 3(100)=300
Savings of Josh =100
Therefore, the savings of Blake and Josh are $300 and $100 respectively.
The goal to proving identities is to transform one side into the other. We can only pick one side to transform while the other side stays the same the entire time. The general rule of thumb is to transform the more complicated side (though there may be exceptions to this guideline).
So I'll take the left hand side and try to turn it into 
One way we can do that is through the following steps:

Since we've shown that the left hand side transforms into the right hand side, this verifies the equation is an identity.
Answer:
B
Step-by-step explanation:
The correct answer is B
2 * x/100 = 8
x/100 = 4
x = 400
400%
Answer:
Using reflexive property (for side), and the transversals of the parallel lines, we can prove the two triangles are congruent.
Step-by-step explanation:
- Since AB and DC are parallel and AC is intersecting in the middle, you can make out two pairs of alternate interior angles<em>.</em> These angle pairs are congruent because of the alternate interior angles theorem. The two pairs of congruent angles are: ∠DAC ≅ ∠BCA, and ∠BAC ≅ ∠DCA.
- With the reflexive property, we know side AC ≅ AC.
- Using Angle-Side-Angle theorem, we can prove ΔABC ≅ ΔCDA.