Need show all work to multiply : ( 2 + sqrt -25 ) ( 4 - sqrt -100 )

58

Step-by-step explanation:

The best thing to do here is to simplify those negative square roots.  I see that you are in imaginary or complex numbers in math right now.  

Simplifying the first negative radical, keeping in mind that i-squared = -1:

Simplifying the next negative radical:

Now we can rewrite those sets of parenthesis without the radicals!

(2 + 5i)(4 - 10i)

FOIL now:

2*4 = 8, then 2*(-10i) = -20i--> 8-20i

5i*4 = 20i, then 5i(-10i) = -50i^2

So altogether this is what we have:

You see that -20i and +20i cancel each other out, leaving us with just

Remember that -1 = i^2, so we can rewrite as:

answer: 1 + 1 = 11

step-by-step explanation:

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.