7(3a + 12) = 168 ← ( divide both sides by 7 )
3a + 12 = 24 ← ( subtract 12 from both sides )
3a = 12 ← ( divide both sides by 3 )
a = 4
OR
distribute the parenthesis by 7
21a + 84 = 168 ← ( subtract 84 from both sides )
21a = 84 ← ( divide both sides by 21 )
a = 4
Answer:
5 times as many should be your answer.
Not all functions have inverse functions. Those that do are called invertible. For a function f: X → Y to have an inverse, it must have the property that for every y in Y, there is exactly one x in X such that f(x) = y.
Answer:
The correct option is (B)
(B) x-y = 6 , 3x+4y = 4
Step-by-step explanation:
As we can see in the graph given below, both lines intersect at (4, -2), which should be the solution of given equations:
Find the values of x and y for (B);
x - y = 6 ⇒ (i)
3x + 4y = 4 ⇒ (ii)
Lets consider equation (i)
x - y = 6
x = 6 + y
Substitute in equation (ii)
3(6+y) + 4y = 4
18 + 3y + 4y = 4
7y = -14
y = -2
Substitute in equation (i)
x - (-2) = 6
x + 2 = 6
x = 6 - 2
x = 4
As solution of part C is also (4, -2), it represents the graph
You can also find the (x, y) for other options the similar way, which will show you they don't have the same value
Because it is simple.you have to do a fewer calculations than if you saved money without it.