y = 2x+3 has a gradient of 2 and a y-intercept of 3.
y = 3x-10 has a gradient of 3 and y-intercept of -10.
When you plot these lines they will intersect at a single point. The answer to solving this question is to find the x-coordinate of this intersection point. You could always check you're answer if you're unsure by solving the equation 2x+3 = 3x-10.