21 kids are in the band
30% of 70 = 21
10u + t is the expressions shows the value of the reversal of digits in a two digit number, t = the tens digit and u = the ones digit. This can be obtained by multiplying 10 with the tens digit and adding unit digit.
<h3>Which is the required expressions?</h3>
Given that, in a two digit number,
t = the tens digit
u = the ones digit
The expression for the digit will be ,
10×t + u = 10t + u
The value of its reversal,
u = the tens digit
t = the ones digit
10×u + t = 10u + t is the required expression
For example,
37 = 10×3 + 7 = 30 + 7 and its reverse 73 = 10×7 + 3 = 70 + 3
Hence 10u + t is the expressions shows the value of the reversal of digits in a two digit number, t = the tens digit and u = the ones digit.
Learn more about algebraic expressions here:
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I will get you started.
x^2+4x-4 = 8
x^2 + 4x - 4 - 8 = 0
x^2 + 4x - 12 = 0
You must now use the quadratic formula.
In the formula, a = 1, b = 4, and c = -12.
Take it from here.