Answer:

Step-by-step explanation:
I believe this is the correct answer. In order to check that my equations are correct I put in some dummy numbers.
a= 2
b=4
c= 
Answer:
3 1/100
Step-by-step explanation:
Place the decimal number over a power of ten.
Answer:
See Explanation
Step-by-step explanation:
Required
Use any 4 consecutive digit from 0 to 9 to form an expression that equals 1 through 30
There is no formula to answer this question. All we need to do is, apply trial by error method to for each expression.
Possible expression and their results are:






























Given:
Total amount invested = $9,000
interest rates = 4% and 6%
Let x be the part of 9,000.
Note that annual return on each investment is the same.
0.04x = 0.06(9,000 - x)
0.04x = 540 - 0.06x
0.04x + 0.06x = 540
0.10x = 540
x = 540/0.10
x = 5,400
0.04x = 0.06(9,000 - x)
0.04(5,400) = 0.06(9,000 - 5,400)
216 = 0.06(3,600)
216 = 216
total interest for the year : 216 + 216 = 432
Interest = pricipal * interest rate * term
432 = 9,000 * interest rate * 1 yr
432/9,000 = interest rate
0.048 = interest rate
Interest rate would be 4.8% to get the same interest from the whole 9,000.
X + y/2 = 1
y/2 = 1 - x
y = 2(1 - x)
y = 2 - 2x
when x = -2
y = 2 + 4
y = 6
(-2,6)
when x = -1
y = 2 + 2
y = 4
(-1,4)
when x = 0
y = 2 - 0
y = 2
(0,2)
when x = 1
y = 2 - 2
y = 0
(1,0)
when x = 2
y = 2 - 4
y = -2
(2,-2)