So, first off it would help if you could define the terms irrational number and integer. Well, an irrational number is basically any real number that can't be expressed as a ratio of integers. They also cannot be represented by terminating or continuing decimals. And an integer is pretty much any number that cannot be written as a fraction or decimal, such as -2, 13, 257. It is not 2 and 1/2, or 4.75. Those would not be integers. Do you think you can figure out the difference?
Answer:
We can write:
x + y = -2
xy = -80
We can rewrite the first equation as x = -y - 2 and then plug that into the second equation to get (-y-2) * y = -80 → -y² - 2y = -80 → y² + 2y - 80 = 0 → (y - 8)(y + 10) = 0 → y = 8, -10. Substituting these values into the first equation we get x = -10, 8 so the answer is (x₁, y₁) = (-10, 8) or (x₂, y₂) = (8, -10).
Use the formula for the conditional probability:

Consider such events
A - a senior takes the bus to school every day;
B - a senior has a driver’s license,
then
,

and

In percent this is nearly 17%.
Answer: correct choice is B.
Actually, the answer is not A, if you're saying A is the first choice above. That's incorrect. You will need to use the Geometric mean for right triangles here to figure out what the value of a is. We will use this form:

. We have a value for YZ of 3; side a is XZ. That means in order to solve this we need WZ, which we can find using pythagorean's theorem. 3^2 + 4^2 = c^2 and 9 + 16 = c^2 and c = 5. Now we fill in accordingly:

. Cross-multiply to get 3XZ=25 and side XZ is

. XZ is 25/3 and YZ is 3, so 25/3 - 3 = XY. That means that XY (side a) = 16/3 or 5 1/3, choice B, or the second one down.
Answer:
Step-by-step explanation:
23x + xy - y + 3y + 5 - 20x + 6xy = 23x - 20x + xy + 6xy -y + 3y + 5
= 3x + 7xy + 2y + 5
Errors:1) The combined coefficients of the x terms should be 3x, not 43x
2) The coefficients of the y terms have been multiplied.
3) The constant was left off.