Solve the simultaneous equations12x+7y= 23,4x+5y= 21.

Sure, let's solve these simultaneous equations step by step.

Step 1: Multiply the second equation by 3 and the first equation by 1 to make the coefficients of x the same in both equations. This gives us:

12x + 7y = 23 12x + 15y = 63

Step 2: Subtract the second equation from the first to eliminate x:

(12x + 7y) - (12x + 15y) = 23 - 63 This simplifies to: -8y = -40

Step 3: Divide by -8 to solve for y:

y = -40 / -8 y = 5

Step 4: Substitute y = 5 into the first equation:

12x + 7*5 = 23 12x + 35 = 23 12x = 23 - 35 12x = -12

Step 5: Divide by 12 to solve for x:

x = -12 / 12 x = -1

So, the solution to the simultaneous equations is x = -1 and y = 5.