Express x^2+4x-7 in the form (x+a)^2-b where a and b are integers

Here, we are required to express x² + 4x - 7 in the form (x+a)² - b and determine the values of a and b.

The values of a and b are 2 and 11 respectively.

By completing the square method;

a = (4/2) = 2.

Therefore, by expanding (x+a)² i.e (x+2)²

We therefore have; x² + 4x + 4

However, the question is given as x²+4x-7

Therefore, by comparison between;

x² + 4x + 4 and x²+4x-7; we have;

4 - b = -7, b = 7+4

Ultimately, b = 11

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It would be 18 cm

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )