With exponents of 10, the exponent really just tells you how many zeroes there are behind the 1. So, for example, 10^4=10000 (4 zeroes behind 1). When multiplying decimals by exponents of 10, you move the decimal to the right, and the amount of places is the exponent number. For example, if I multiply 5.34 by 10^2, I move the decimal over to the right 2 times and get 534.
So, if you just multiply these you get 9.36*10000, which is 93600.
To let the variable alone you can follow these steps: 1) subtract 228 from both sides 2) divide both sides by 4. This is the solution: 1) 4y + 228 - 228 = 352 - 228 => 2) 4y = 124 => 3) (4y)/4 = 124/4 => 4) y = 31. Then, <span>the answer is the option A. y = 31. </span>
(2x + 3y = 12) x (-2)
(4x - 3y = 6) x 1
-4x - 6y = -24
4x - 3y = 6
You can cancel out the x values by adding the two equations together.
(-4x + 4x) + (-6y - 3y) = (-24 + 6)
-9y = -18
y = 2
Solve for x now...
4x - 3(2) = 6
4x - 6 = 6
4x = 12
x = 3
Check... (x = 3, y = 2)
2(3) + 3(2) = 12
6 + 6 = 12
12 = 12 <- this works!
4(3) - 3(2) = 6
12 - 6 = 6
6 = 6 <- this works!
