(a-21)(350-10a)=400(a-21)(350-10a)=400350a-10a^2-7350+210a=40010a^2-560a+7750=0a^2-56a+775=0(a-25)(a-31)=0a-25=0,a-31=0a=25或31像这种题怎么才能知道775分解成什么才的56,是一个一个试的吗?
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 22:44:44
![(a-21)(350-10a)=400(a-21)(350-10a)=400350a-10a^2-7350+210a=40010a^2-560a+7750=0a^2-56a+775=0(a-25)(a-31)=0a-25=0,a-31=0a=25或31像这种题怎么才能知道775分解成什么才的56,是一个一个试的吗?](/uploads/image/z/14762843-35-3.jpg?t=%28a-21%29%28350-10a%29%3D400%EF%BC%88a-21%29%28350-10a%29%3D400350a-10a%5E2-7350%2B210a%3D40010a%5E2-560a%2B7750%3D0a%5E2-56a%2B775%3D0%28a-25%29%28a-31%29%3D0a-25%3D0%2Ca-31%3D0a%3D25%E6%88%9631%E5%83%8F%E8%BF%99%E7%A7%8D%E9%A2%98%E6%80%8E%E4%B9%88%E6%89%8D%E8%83%BD%E7%9F%A5%E9%81%93775%E5%88%86%E8%A7%A3%E6%88%90%E4%BB%80%E4%B9%88%E6%89%8D%E7%9A%8456%2C%E6%98%AF%E4%B8%80%E4%B8%AA%E4%B8%80%E4%B8%AA%E8%AF%95%E7%9A%84%E5%90%97%3F)
(a-21)(350-10a)=400(a-21)(350-10a)=400350a-10a^2-7350+210a=40010a^2-560a+7750=0a^2-56a+775=0(a-25)(a-31)=0a-25=0,a-31=0a=25或31像这种题怎么才能知道775分解成什么才的56,是一个一个试的吗?
(a-21)(350-10a)=400
(a-21)(350-10a)=400
350a-10a^2-7350+210a=400
10a^2-560a+7750=0
a^2-56a+775=0
(a-25)(a-31)=0
a-25=0,a-31=0
a=25或31
像这种题怎么才能知道775分解成什么才的56,是一个一个试的吗?
(a-21)(350-10a)=400(a-21)(350-10a)=400350a-10a^2-7350+210a=40010a^2-560a+7750=0a^2-56a+775=0(a-25)(a-31)=0a-25=0,a-31=0a=25或31像这种题怎么才能知道775分解成什么才的56,是一个一个试的吗?
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