Answer:
26
Step-by-step explanation:
21 + 2=22
2+2=4
22+4=26

Here, we want to get what Andre's mistake was and correct it
To answer this, we are supposed to use the division law of indices
We have this as;

Now, in the case of this question, x is 4 and y is -3
So, we have the expression as;

His mistake is thus adding the exponents instead of subtracting
Step 1: Cross-multiply.
(x+3)^1/2=(3x+7)^1/4
Step 2: Subtract 6x from both sides.
4x+12−6x=6x+14−6x
−2x+12=14
Step 3: Subtract 12 from both sides.
−2x+12−12=14−12
−2x=2
Step 4: Divide both sides by -2.
−2x/−2=2/−2
Answer:
x=−1