Vertex aka max or min point is found by -b/2a in form
f(x)=ax^2+bx+c
f(x)=-1x^2+8x+20
vertex x value is -8/(2)(-1)=-8/-2=4
input back to find y value
f(4)=-(4^2)+8*4+20
f(4)=-16+32+20
f(4)=36
max (since the graph opens down) is (4,36)
axis of symmetry is the x coordinate
max is (4,36)
axis of symmetrry is x=4
X + y = 62
x - y = 12
Move x over so y is alone in one of the above equations,
y = 62-x
Now substitte in y
x-(62-x) = 12
x - 62 + x = 12
2x = 12 + 62
2x/2 = 74/2
x = 37
Now for y sub in the x!
x + y = 62
(37) + y = 62
y = 62 - 37
y = 25.
So 25 + 37 =62
and 37 - 25 = 12
Method 2 :
Start by stacking the 2 original equations from above,
x+y=62
x-y=12
You want to "cancel" out one of the variable so,
x+y=62
+ + = +
x - y =12
So then you add,
2x = 74
2x / 2 = 74 / 2
x = 37.
Now you can once again sub it back into the original equation to solve for y,
x+y=62
(37)+y=62
y=62-37
y=25
Hope this helps!
Answer:
niw9
Step-by-step ethats gsggdd
