Refer to the forumla x+a/b=(x+b)/a
a)make x the subject of the formula
b)if a=5 and b=(-3),find x
math++
2007-09-08 8:04 pm
回答 (3)
2007-09-08 8:09 pm
✔ 最佳答案
Refer to the forumla x+a/b=(x+b)/aa)make x the subject of the formula
x + a/b = (x + b)/a
a(x + a/b) = x + b
ax + a^2/b = x - b
a^2/b + b = x - ax
(a^2/b + b) = x(1- a)
(a^2/b + b)/(1 - a) = x
b)if a=5 and b=(-3),find x
x = [(5)^2/(-3) + (-3)] / (1 - 5)
x = 16/3 / -4
x = - 4/3
2007-09-08 8:49 pm
a) x+a/b=(x+b)/a
(bx+a)/b=(x+b)/a
a(bx+a)=b(x+b)
abx+a^2=bx+b^2
abx-bx=b^2-a^2
x(ab-b)=b^2-a^2
x=(b^2-a^2)/(ab-b)
b) put a=5 and b=(-3)
x=(b^2-a^2)/(ab-b)
x=((-3)^2-(5)^2)/((5)(-3)-(-3))
x= -16/-12
x= 4/3
(bx+a)/b=(x+b)/a
a(bx+a)=b(x+b)
abx+a^2=bx+b^2
abx-bx=b^2-a^2
x(ab-b)=b^2-a^2
x=(b^2-a^2)/(ab-b)
b) put a=5 and b=(-3)
x=(b^2-a^2)/(ab-b)
x=((-3)^2-(5)^2)/((5)(-3)-(-3))
x= -16/-12
x= 4/3
參考: me
2007-09-08 8:15 pm
a) xa+(a^2)/b=x+b
(a^2)/b-b=x-xa
(a^2)/b-b=x(1-a)
((a^2)/b-b)/(1-a)=x
b) ((5^2)/(-3)-(-3))/(1-5)=x
x=(25/(-3)+3)/(-4)
=((25+9)/(-3))/(-4)
=34/12
=17/6
(a^2)/b-b=x-xa
(a^2)/b-b=x(1-a)
((a^2)/b-b)/(1-a)=x
b) ((5^2)/(-3)-(-3))/(1-5)=x
x=(25/(-3)+3)/(-4)
=((25+9)/(-3))/(-4)
=34/12
=17/6
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