`a,(−2)^2 × ( -25 ) × ( +5 ) × ( -4 )`
`=4 × ( -25 ) × ( 5 ) × ( -4 )`
`=(4 ×5) xx( -25 × ( -4 ))`
`=20xx100`
`=2000`
`b, 11 × 62 + 12 × ( -11 ) + 50 × 11`
`= 11 ×( 62 -12 + 50)`
`=11xx100`
`=1100`
`c, 2 × ( -4 - 14 ) ÷ ( -3 ) `
`= 2 × (-18) ÷ ( -3 ) `
`=(-36)-:(-3)`
`=12`