好急!!2次公式4條數

1. 3分之20 P=224-p^2
(20/3)p=224-p^2
20p=672-3p^2
3p^2+20p-672=0
(3p+56)(p-12)=0
3p+56=0 or p-12=0
Therefore, p=-56/3 or p=12

2. 12x^2+x-34=0
√(b^2-4ac)=√(1^2-4(12)(-34))=√1633=40.41
(有無抄錯題目呀？無整數答案呀)

3. 16分之7 q^2+8分之9 q-2分之5=0
(7/16)q^2+(9/8)q-(5/2)=0
7q^2+18q-40=0
(7q-10)(q+4)=0
7q-10=0 or q+4=0
Therefore, q=10/7 or q=-4

4. (4-x)(4+x)=(2x+5)(5x-2)
16-x^2=10x^2+25x-4x-10
11x^2+21x-26=0
√(b^2-4ac)=√(21^2-4(11)(-26))=√1585=39.81
(有無抄錯題目呀？無整數答案呀)