If you solve by substitution , you would get and the equation -3x-2(5x-7)=12 which if you solve becomes a -3x-10x+14=12 You than want to combine like terms , so you combine -3x and -10x and bring the other problem down. -13x+14=12 You subtract the 14 from itself and the 12 to leave -13 with its variable alone. Now you should have -13x=-2 You divide both sides by -13 and you’ll get x=2/13 Next step is you plug back this answer to the y=5x-7 And you’ll get y= -81/13
The two white triangles have areas of 1/2 x 3 x 10 and 1/2 x 6 x 10 = 15 + 30 = 45 cm^2 The shaded area will be 10 x 10 - 45 = 55 cm^2 The percentage shaded = 55 / 100 x 100% = 55%
