Q. −7x25y=(y+5)(y−5)=15xIf (a,b) is a solution to the system of equations shown and a>0, what is the value of a ?
Simplify second equation: We have the system of equations:1) −7x2=(y+5)(y−5)2) 5y=15xFirst, let's simplify the second equation to find a relationship between x and y.5y=15xDivide both sides by 5 to isolate y:y=3x
Substitute y=3x: Now, let's substitute y=3x from the second equation into the first equation to solve for x.−7x2=((3x)+5)((3x)−5)
Expand right side of equation: Next, we will expand the right side of the equation using the difference of squares formula:−7x2=(3x+5)(3x−5)−7x2=9x2−25
Move terms to one side: Now, let's move all terms to one side of the equation to set it equal to zero:−7x2−9x2+25=0Combine like terms:−16x2+25=0
Solve for x2: To find the value of x, we need to solve for x2: -16x2=−25 Divide both sides by -16: x2=1625
Find value of x: Taking the square root of both sides gives us two possible solutions for x:x=±1625x=±45Since we are looking for the positive value of a (and a corresponds to x), we choose the positive solution:a=45
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