Answer: Read Sol.
Step-by-step explanation: To solve these, call each given zero = z. The function is when given a zero that is an integer (x-z1)(x-z2)(x-z3)... so on until all zeroes are used. This works for fractions also. But when you have irrationals, you will have to make sure each irrational solutions conjugate is there. So if a given zero is 2-sqrt3, then always 2+sqrt3 will also be a 0. Likewise, if given -4-sqrt7, then -4+sqrt7 will also always be a zero. Use this logic to solve them very quickly! I hope this helps!
Answer: (6 , 3)
Step-by-step explanation: Given
x + 3y =15 ------- equation 1
4x + 2y = 30 --------- equation 2
x = 15 - 3y
Put value of x in equation 2
4 (15 - 3y) + 2y = 30
60 - 12y + 2y = 30
-10y = -30
divide by '-10' on both sides
y = 3
now, put value of y in equation 1
x + 3(3) = 15
x + 9 = 15
x = 15 - 9
x = 6
So , (x , y) = (6 , 3)
N + d = 21
0.5n + 0.10d = 1.35
5n + 10d = 135
d = 21-n
5n + 210 - 10n = 135
-5n = -75
n = 15
d = 6
The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.
The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.
