Answer:
x=9
Step-by-step explanation:
hope this helps i think it's right 60=9x - 21 you add 21 to both sides and get 81 = 9x then divide 81 by 9 and get x=9
Answer:
the third option
Step-by-step explanation:
what does that mean ?
to "rationalize" it is to transform it into a rational number (that is a number that can be described as a/b, and is not an endless sequence of digits after the decimal point without a repeating pattern).
a square root of a not square number is irrational (not rational).
so, what this question is asking us to get rid of the square root part in the denominator (the bottom part).
for this we need to multiply to and bottom with the same expression (to keep the whole value of the quotient the same) that, when multiplied at the bottom, eliminates the square root.
what can I multiply a square root with to eliminate the square root ? the square root again - we are squaring the square root.
so, what works for 9 - sqrt(14) as factor ?
we cannot just square this as
(9- sqrt(14))² = 81 -2sqrt(14) + 14
we still have the square root included.
but remember the little trick :
(a+b)(a-b) = a² - b²
without any mixed elements.
so, we need to multiply (9-sqrt(14)) by (9+sqrt(14)) to get
81-14 = 67 which is a rational number.
therefore, the third answer option is correct.
Answer:
x = 17 and y = 37
Step-by-step explanation:
Let the numbers be x and y.
y = 3 + 2x
xy = 629
substituting y in the second equation we get
x(3+2x) = 629
3x + 2
= 629
2
+ 3x - 629 = 0
Solving a quadratic equation by using its formula:
x = [-3 ±√(9-4(2)(-629)] / 4
x = [-3 ± √5041] / 4
x = [-3 ± 71] / 4
x = 17 and 
Ignore the negative number in x and just use x = 17 in the first equation we get
y = 3 + 2(17) = 37
Answer:
Step-by-step explanation:
-3x^2 --2x--2 -- 9/x--2
It literally means writing it out: seventeen