Answer:
answer in the picture
Step-by-step explanation:
Answer:
a) It's a quadratic
b) f(x) = A(x-3)(x-7)
c) she is right
Step-by-step explanation:
(0-12)/(3-1) = -6
(-4-0)/(5-3) = -2
Since the slope is not constant, it can't be a linear.
Therefore a quadratic
Since the zeroes are 3 and 7,
Factors are (x - 3) and (x - 7)
f(x) = A(x - 3)(x - 7)
Use any one point besides the x-intercepts to find A
12 = A(1-3)(1-7)
12 = 12A
A = 1
f(x) = (x - 7)(x - 3)
f(x) = x² - 7x - 3x + 21
f(x) = x² - 10x + 21
She is right
Answer:
Breadth = 15 cm
Step-by-step explanation:
Area = length x breadth
315 = 21 x breadth
[ dividing both sides by 21 ]

Pls mark me brainiless
(4/5)(x - 2) = 18
4(x - 2) = 90
4x = 98
x = 24 1/2
It depends on what variable you are tying to solve for first. Say you are trying to solve for x first and then y on the first problem you wrote.
In substitution you solve one of the equations for example with
6x+2y=-10
2x+2y=-10
you solve 2x+2y=-10 for x
2x+2y=-10
-2y = -2y (what you do to one side of the = you do to the other)
2x=-10-2y (to get the variable by its self you divide the # and the variable)
/2=/2 (-10/2=-5 and -2y/2= -y or -1y, they are the same either way)
x=-5-y
now you put that in your original equation that you didn't solve for:
6(-5-y)+2y=-10 solve for that
-30-6y+2y=-10 combine like terms
-30-4y=-10 get the y alone and to do this you first get the -30 away from it
+30=+30
-4y=20 divide the -4 from each side
/-4=/-4 (20/-4=-5)
y=-5
now the equation you previously solved for x can be solved for y.
x=-5-y
x=-5-(-5) a minus parenthesis negative -(- gives you a positive
-5+5=0
x=0
and now we have solved the problem. x=0 and y=-5