Find the value of x. The diagram is not to scale. Given:

RS=~ST,m<RST=7x-54,m<STU=8x

Since RS is congruent to ST, the angles opposite to these sides, angle RST and angle STU, are also congruent. Therefore, we can set up the following equation:

7x - 54 = 8x

To solve for x, we can subtract 7x from both sides:

-54 = x

Therefore, the value of x is -54.