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diff --git a/14/CH7/EX7.7/example_7_7.sce b/14/CH7/EX7.7/example_7_7.sce
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+//chapter 7
+//Example 7.7
+//Page 186
+//matrixmodification
+clear;clc;
+//Voltage Sources
+Ea = 1.5;
+Eb = 1.5*(cos(-36.87 * %pi / 180) + %i * sin(-36.87 * %pi / 180))
+Ec = 1.5;
+//admittances
+Ya = -%i*0.8;
+Yb = Ya;
+Yc= Ya;
+Yd = -%i*5;
+Ye = -%i*8;
+Yf = -%i*4;
+Yg = -%i*2.5;
+Yh = Yd;
+//Capacitor
+Zb = -%i * 5
+//current sourcs
+I1 = Ea * Ya;
+I2 = Eb * Yb;
+I3 = I1;
+I4 = 0;
+//Self-admittances
+Y11 = Yd + Yf + Ya;
+Y22 = Yh + Yg + Yb;
+Y33 = Ye + Yc + Yg + Yf;
+Y44 = Yd + Ye + Yh;
+//Mutual-admittances
+Y12 = 0;Y21 = Y12;
+Y13 = -Yf;Y31 = Y13;
+Y14 = -Yd;Y41 = Y14;
+Y23 = -Yg;Y32 = Y23;
+Y24 = -Yh;Y42 = Y24;
+Y34 = -Ye;Y43 = Y34;
+//Matrix Form
+I = [I1 ; I2 ; I3 ; I4];
+Y = [Y11 Y12 Y13 Y14;Y21 Y22 Y23 Y24;Y31 Y32 Y33 Y34;Y41 Y42 Y43 Y44];
+V = Y\I;
+Z = inv(Y);
+disp('Original bus impedance matrix')
+disp(Z)
+[m,n] = size(Z)
+for i = 1:m
+    for j = 1:n
+    Z(5,i) = Z(i,j);
+    Z(i,5) = Z(i,j)
+    end
+end
+Z(5,5) = Z(4,4) + Zb;
+disp('Modified bus impedance matrix')
+disp(Z)
+[m1,n1] = size(Z);
+Z_new = zeros(m1-1,n1-1);
+for c = 1:m1-1
+    for d = 1:n1-1
+    Z_new(c,d) = Z(c,d) - ((Z(c,5)*Z(5,d)) / Z(5,5));
+    end
+end
+disp('Modified bus impedance matrix after eliminating fifth row and column')
+disp(Z_new)
+V_4 = Z_new(4,:) * I;
+printf("\n V4 = %.2f /_%.2f per unit \n\n",abs(V_4),atan(imag(V_4),real(V_4)) * 180 / %pi)
+disp('V4 same as found in Example 7.6')
\ No newline at end of file
diff --git a/14/CH7/EX7.7/result_ex_7_7.txt b/14/CH7/EX7.7/result_ex_7_7.txt
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+ Original bus impedance matrix   
+ 
+    0.4774405i    0.3705997i    0.4019598i    0.4142155i  
+    0.3705997i    0.4871730i    0.3922274i    0.4125934i  
+    0.4019598i    0.3922274i    0.4558128i    0.4231910i  
+    0.4142155i    0.4125934i    0.4231910i    0.4733096i  
+ 
+ Modified bus impedance matrix   
+ 
+    0.4774405i    0.3705997i    0.4019598i    0.4142155i    0.4142155i  
+    0.3705997i    0.4871730i    0.3922274i    0.4125934i    0.4125934i  
+    0.4019598i    0.3922274i    0.4558128i    0.4231910i    0.4231910i  
+    0.4142155i    0.4125934i    0.4231910i    0.4733096i    0.4733096i  
+    0.4142155i    0.4125934i    0.4231910i    0.4733096i  - 4.5266904i  
+ 
+ Modified bus impedance matrix after eliminating fifth row and column   
+ 
+    0.5153434i    0.4083541i    0.4406840i    0.4575258i  
+    0.4083541i    0.5247796i    0.4307999i    0.4557341i  
+    0.4406840i    0.4307999i    0.4953761i    0.4674398i  
+    0.4575258i    0.4557341i    0.4674398i    0.5227987i  
+
+ V4 = 1.58 /_-11.97 per unit 
+
+ 
+ V4 same as found in Example 7.6