`0.03x + 0.04y = 0.52, 0.02x - 0.05y = -0.19` Find the angle theta (in radians and degrees) between the lines

Given 

`0.02x-0.05y=-0.19`

`0.03x+0.04y=0.52` 

Find the slope of line 1.

`0.02x-0.05y=-0.19`

`2x-5y=-19`

`-5y=-2x-19`

`y=2/5x+19/5`

The slope of line 1 is `m_1=2/5.`

Find the slope of line 2.

0.03x+0.04y=0.52

`3x+4y=52`

`4y=-3x+52`

`y=-3/4x+13`

The slope of line 2 is `m_2=-3/4.`

Find the angle of inclination between the lines using the formula

`tan(theta)=|(m_2-m_1)/(1+m_1m_2)|`

`tan(theta)=|((-3/4)-(2/5))/(1+(-3/4)(2/5))|`

`tan(theta)=(23/20)/(14/20)=23/14`

` ` `theta=arctan(23/14)=58.7^@=1.0240`  radians

The angle between the lines is 58.7 degrees or 1.0240 radians.