is this done correctly 1 15 x2x28x 52 b 28 2a 22 727z 26752

is this done correctly?

1 15 (x)-2x+28x- 52 b 28 2a 2(-2) (7)--2(7)z + 26(7-52 /(7) =-98 + 182-S2 f7) 32 Maximum at (7.32)

Solution

You are very close. You got x cordinate correctly but there need to fix something in y cordinate. You did a mistake, there should be 28*7 instead of 26*7.

Given equation represents a downward parabola and maximum at the vertex. And we can find the vertex as

x cordinate of vertex = -b/2a = 7

y -cordinated of vertex = f(-b/2a) = f(7) = -2(7)^2 +28*7-52 = 46

Hence maximum value = 46 at x= 7