Answer
Step-by-step explanation: cube
Answer:

Step-by-step explanation:
Let's examine the following general product of two binomials with variables x and y in different terms:

so we want the following to happen:

Notice as well that
means that those two products must differ in just one unit so, one of them has to be negative, or three of them negative. Given that the product
, then we can consider the case in which one of this (b or d) is the negative factor. So let's then assume that
are positive.
We can then try combinations for
such as:

Just by selecting the first one 
we get that 
and since

This quadratic equation give as one of its solutions the integer: d = -2, and consequently,

Now we have a good combination of parameters to render the factoring form of the original trinomial:

which makes our factorization:

60i
if you go to mode on your calculator then Chang it from "real" to "a+bi" you can solve for unreal numbers. if you press "2nd" then "." it makes an "i"
15=3b
15/3 = 3b/b
5= b
Isolate the variable by diving 3 on both sides
Answer:
otterbox costs $95; beats costs $210
Step-by-step explanation:
x = otterbox y = beats
4x + 2y = 800 y = 2x + 20
4x + 2(2x + 20) = 800
4x + 4x +40 = 800
8x + 40 = 800
8x = 800 - 40
8x = 760
x = 760 / 8
x = 95 Otterbox costs $95 each
4x + 2y = 800
4(95) + 2y = 800
380 + 2y = 800
2y = 800 - 380
2y = 420
y = 420 / 2
y = 210 Beats costs $210
4(95) + 2(210) = 800
380 + 420 = 800