Answer:
9.6
Explanation:
Plugging in the info given, we get:
2(4) - (2/5)(-4) = 8 - (-8/5) = 8 + 8/5
From here, you need to make the denominators of both numbers the same in order to combine them further. Currently, as a fraction, it looks like this:
8/1 + 8/5
To make the denominators the same we can just multiply 8/1 by 5/5 (this is the same as multiplying by 1, which essentially allows us to change it's form without changing its value). Doing that gives:
(8/1)(5/5) + 8/5 = (8•5)/5 + 8/5 = 40/5 + 8/5
= (40+8)/5 = 48/5
So 48/5 is the answer. But the website wants you to put it into decimal form. This can be done using a calculator, but let's pretend we don't have one...
Decimals work by using whole numbers divided by multiples of 10 and can be visualized as moving a decimal left (or right) between numbers. For example:
1/10 = 0.1
4/10 = 0.4
23/10 = 2.3
13/100 = 0.13
59/1000 = 0.059 and so on.
So if we can multiply 48/5 by something to make the denominator some multiple of 10, we can simply move the decimal left once and that's our answer. 2/2 should work here:
(48/5)(2/2) = (48•2)/(5•2) = 96/10 or 96.0/10
96.0/10 = 9.6
So your decimal answer is 9.6.