Find the maximum value of the following format: (1) y = 2x & # 178; + 8x + 9 (2) y = - 2x & # 178; + 3x + 7

Find the maximum value of the following format: (1) y = 2x & # 178; + 8x + 9 (2) y = - 2x & # 178; + 3x + 7

analysis
(1)y=2[(x+2)^2-4]+9
=2(x+2)^2-8+9
=2(x+2)^2+1
When x = - 2, the minimum value is 1
(2)y=-2x²+3x+7
Axis of symmetry x = - B / 2A = 3 / 4
The maximum value is obtained when x = 3 / 4
65/8