So the solution is that x can be any real number if ( bd = ab) , otherwise (x = 0 ).
To solve for x in the equation
![\[ (a + bx)/(a + b) = (c + dx)/(c + d) \]](https://img.qammunity.org/2024/formulas/mathematics/college/y8uxy6tdbshaj1a97nvhdhz0dwr4dgoy94.png)
given that cb = ad , we can cross-multiply to eliminate the fractions:
![\[ (a + bx)(c + d) = (c + dx)(a + b) \]](https://img.qammunity.org/2024/formulas/mathematics/college/mngaga7iwv2gh3nive5t3duizkwzfcut4t.png)
Expanding both sides:
![\[ ac + adx + bcx + bdx = ac + abx + cdx + cbd \]](https://img.qammunity.org/2024/formulas/mathematics/college/z3xeact39sxqq2psvt9xh8z1nh183lqt5u.png)
Using the given condition cb = ad , we can simplify the equation:
![\[ ac + adx + adx + bdx = ac + abx + cdx + adx \]](https://img.qammunity.org/2024/formulas/mathematics/college/9r4apbou5fwfui76arosw11wcb36agx5if.png)
Combine like terms:
![\[ ac + 2adx + bdx = ac + abx + cdx + adx \]](https://img.qammunity.org/2024/formulas/mathematics/college/ebwu562yjbwq8p1p8yn1jtz2wkus7nplfe.png)
Since ac appears on both sides of the equation, we can cancel it out:
![\[ 2adx + bdx = abx + cdx + adx \]](https://img.qammunity.org/2024/formulas/mathematics/college/fsey7putsxtl0s7cx0wmv8jgo8bcyhse43.png)
Now we have an equation with terms containing x on both sides. Since we want to solve for x , we can gather all terms involving x on one side of the equation:
![\[ 2adx + bdx - abx - cdx - adx = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/k6im1iqxi3tz8k6wyalervdhdecfg7gfse.png)
Simplify by combining like terms:
![\[ adx + bdx - abx - cdx = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/m81f6veokf69jsnl7mbaqn25yuuiwga1km.png)
Now, we factor out an x from each term:
![\[ x(ad + bd - ab - cd) = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/szs092dbft3q5x6jtmx4o3x7o5hkk2vj85.png)
To solve for x , we can divide both sides by the factor
provided that this factor is not equal to zero. However, since we have cb = ad , the equation simplifies to:
![\[ x(ad + bd - ab - cb) = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/12mk3m0si24zl9f4dtizu2eurzgge78pr2.png)
![\[ x(ad + bd - ab - ad) = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/vo3npjc8qojna3arfsoksyaheqb696voss.png)
![\[ x(bd - ab) = 0 \]](https://img.qammunity.org/2024/formulas/mathematics/college/k0uls77gsb18w6c0zxf4ok52yy2cemahvn.png)
Now, if
then we would have x times 0 which gives us no information about x (since any number times 0 equals 0). Therefore, if
x can be any real number. If
then x must be 0 to satisfy the equation.